YMMV / Land of the Lustrous

• Abandon Shipping:
  • Some abandoned the Phos/Cairngorm ship come Chapter 69, where the Prince told Cairngorm they were being mind controlled into caring for Phos.
  • Others abandoned Rutile/Padparadscha after Rutile tried to shatter Padparadscha and Padparadscha shatters Rutile in self-defense, finding Rutile's vow to repair Padparadscha (and going so far as to trying to shatter them to do so) had become an unhealthy obsession.
  • Cinnabar/Phos fans became nearly nonexistent after Cinnabar joined the rest of the Earth gems and did not bother to even speak to Phos, much less defend them, when the Earth gems turned on them.
• Accidental Innuendo: There was a bit of confusion when Ghost first talked about the "Gem inside of [them]", making some readers think Ghost was pregnant.
• Alternate Character Interpretation:
  • Diamond's frustration that they Can't Catch Up to Bort is depicted as either a tragic struggle to be seen as a true equal to their partner, or an irrational and petty grudge perpetuated by their refusal to take Bort's words to heart.
  • Phos' betrayal of Sensei is sometimes thought to be less them lashing out at an authority figure who won't do his job and won't tell them the truth and more the Gem equivalent to a growing teen's rebellious phase.
  • The reveal of the connection between Sensei and the Moon People spawned plenty of this for both parties. Why did Sensei stop praying for the souls of humanity, and is he in the wrong for not doing so, given that the gems are only being hunted because of it? The Moon Peoples' inability to pass on possibly makes them more sympathetic, but at the same time doesn't change the fact that they're torturing innocent beings.
  • Phos making a bargain with the Moon People: are they making a tough, but necessary, decision to gain the best possible outcome for those that they care about, or have they turned into a traitorous Manipulative Bastard?
    • Furthermore, can Phos even be considered the same being they were at the start of the series, or has Lapis's head taken over their body?
  • How much of what Aechmea says is him being truthful, and how much of it is him just saying what the Gems want to hear? What are his true goals? Does he really care about "passing on", or does he have something else in mind? And does he really love Cairngorm, or is he stringing them along as part of a larger plan? Or is it all true?
  • With Chapter 68 stating that Cairngorm was being mind controlled into going along with whatever Phos wanted, questions arise as to how much Cairngorm likes Phos, if at all, or if Cairngorm isn't influenced by Ghost but just made to feel that way. Made even more complicated when Cairngorm stabs Phos in the head completely unnecessarily after being freed from mind control. Still others surmise that Cairngorm is forcing themself to push away all reminders of their old life, given their huge insecurities about their identity and how the information we already received both from Ghost and from Cairngorm's actions contrast drastically with their new persona. The Party At the End implies through Ghost that it really was just as Aechmea said, and Cairngorm was being influenced by Ghost's leftover inclusions.
  • Does Rutile really care about Padparadscha and wish to see the Gem fixed, or was Rutile using fixing Padparadscha as an excuse to keep a steady duty, considering how mad they were at Pad getting taken to and fixed at the Moon? Or is it a bit of both? Was Rutile trying to win Padparadscha's Undying Loyalty that the gem offered to Phos when Phos ends up being responsible for saving Padparadscha?
  • Did Professor Ayumu reincarnate as Phos? Or was she really just dreaming? Were her final words part of Sensei's memory, or a presence similar to Lapis, directing her words to Phos?
  • Considering the many, many visual parallels between Sensei and Antarticite and Aechmea and Cairngorm, some fans came to the conclusion that the former duo is actually as romantic as the latter rather than the parental relationship Sensei has with all of the Gems, at least to the Lustrous' limited understanding of romance.
• Awesome Art: Both the manga and anime count for this. The manga conveys its action with striking minimalist compositions, while the anime keeps to the style of the manga and makes everyone expressive and beautiful in 3D.
• Awesome Music: The opening, "Kyoumen no Nami" (or translated as "A Wave on the Mirror's Surface"), which reflects the Innocence Lost Coming of Age with its youthful voice and an instrumental searching for a grander scheme in the chorus only to fall into something slow & dramatic, as well as the elegance and struggling story of the Gems with the usage of the violin, piano, and guitar.
• Arc Fatigue: It’s been agreed upon by some of the fandom that the moon arc has plenty of Deus Angst Machina, an unnecessary and uncomfortably continuous focus on Unequal Pairing Cairngorm and The Prince and the story seemingly drags on the point that certain gems can not be returned from dust after giving the readers as well as the gems themselves false hope once again that certain gems, particularly Antarc, had a chance to return. It doesn’t help that the arc is heavily laden with Villain Decay for the moon people the longer the gems remain with them, which is a point of contention in some of the fandom. Worse off, by the time the story had begun to move anywhere again, the fandom had largely begun to dissipate... at least in the west.
• Ass Pull: Some readers find the Lunarian conversion machine and the inclusions gathering in the ice pit to be too convenient a solution for the problems the races have. Not only does it allow the Lustrous to revive nearly every one of their lost members, but it took a comparatively shorter time to build it compared to all of the other plans the Lunarians tried over the years, and it works perfectly fine on organic lifeforms like the Admirabilis.
• Base-Breaking Character:
  • Phos. Some see the Gem as a lovable screw-up, and being one of the few people willing to actively pursue a solution for the Lustrous/Lunarian conflict, are willing to forgive the more unsavory acts they commit. Others find Phos too selfish and shortsighted especially when it comes to large plans, and are offput by Phos' many failures across the series.
  • Cinnabar as the manga goes on. Some feel bad for their isolation issues and do like their presence in the story due to how they interact with Phos and others, but some feel that the gem's predicament is entirely their own fault for being contradictory and dishonest about their desires, and that they've overstayed their welcome in relevance given they only appear every so often in minor, but irrelevant roles. Other fans feel that Cinnabar is dismissive of Phos or an ungrateful, given that Phos ultimately was the reason the other Gem begins interacting with the Lustrous again and yet Cinnabar doesn't try to hear the Gem out in the post-moon arcs. Them using their mercury to incapacitate and seriously harm fan favorite Padparadscha, and being the one to suggest splitting Phos up and burying them (albeit where the alternative was Rutile's suggestion of scattering the Gem's pieces into the ocean) lost the gem several fans, with calls beginning to have Cinnabar killed off in retribution. To put it bluntly, they got their wish. If there's one thing Phos didn't forget, it was Cinnabar's betrayal that led to their current situation and desire for vengeance. Phos tore Cinnabar apart and absorbed their mercury for themselves.
  • Diamond slowly became more contentious as time went on. There are some who believe they get too much credit for being a stagnant, supporting character and a number of fans became tired of their popularity. It also doesn't help that they are already in a Broken Base scenario with Bort over their partnership issues in which they are seen as a huge part of the problem by people who are team Bort in particular. Just like Cinnabar, a lot of fans are sore about how they get replaced as Bort's partner by Zircon and Demoted to Extra once their character arc finishes.
  • Similarly, some people find Bort to be too mean to like, and blame them for their relationship with Dia crumbling apart, while others find Bort badass or their Brutal Honesty refreshing and just what several gems need.
  • Cairngorm has come under some heavy criticism before and after the Moon arcs. As a completely different pace from Ghost, some found Cairngorm too blunt or violent, while others admired the character's honesty and partnership with Phos. Post moon, the opinion on the gem breaks further considering their embracing becoming the Moon Princess.
  • Euclase in the second half of the series has gotten a lot of criticism thanks to the Moon arc. Because they were willing to talk to Phos, was the first to accept Sensei once he stepped down as the Lustrous' leader, and feels some remorse for Phos' trials, a portion of the Western audience found Euclase the most sympathetic of the Earth Gems. However, there are just as any people calling Euclase an ineffectual hypocrite because while they are visibly concerned, they're considered an Accomplice by Inaction by standing with the Earth Gems even after the group considers Phos a traitor and when they're all whisked away to the Lunarians.
• Broken Base: The anime has been this for a lot of fans:
  • Whether gender neutral pronouns should be used for the gems has become this, arguing whether the gems are truly genderless or just sexless. Most English speaking fans seem to have a firm opinion on whether they are genderless, male, or female. However, this seems to only be an issue with the English-speaking fanbase. In response to the pronoun debate, some fans have simply opted to using masculine pronouns "He/Him" for the gems because that's what the source material does, or simply using "They/Them" because that is the easiest gender neutral way of referring to the gems. Gendering the gems based on what they believe the gems identify as has become a thing within the Western (mainly, English) fanbase as well. This trope is very sure to be even more controversial in Spanish, as that language doesn't have gender-neutral pronouns unlike East Asian languages and English.^note It does allow, and actively encourages, omission of personal pronouns. Possessive pronouns are all gender-neutral too, so taking both factors into account, it's still very much possible to keep a text in Spanish both correctly and, more importantly, naturally gender-neutral .
  • Who's more at fault for their failing relationship, Bort or Diamond? There's a surprisingly large debate on it and many start to take sides. Those on Team Bort find Dia to be massively insecure, and their inferiority complex and refusal to listen to Bort's advice leads them to let their partnership worsen. Team Diamond meanwhile finds Bort to be unwittingly cruel, and because of their no-nonsense mindset and lack of social skills they can't quite understand what Diamond is going through or how they feel, causing their fallout.
  • The statement of Ghost compelling Cairngorm to protect Phos or sway the Gem's mode of thought is this for quite a few fans. Some believe the claim reduces Ghost to a parasite that's deprived Cairngorm of all free will, and state it does a disservice to both characters. On the other hand, some believe that there's a real kernel of truth to it, and are glad that Ghost is gone as it means Cairngorm can be their true self without the influence of another.
  • Whether the Lunarians deserve sympathy given their Tragic Backstory as human souls unable to pass on to the next world. Some fans still consider them evil and not to be trusted, pointing out Aechmea's shady nature and the strange focus he has on Cairngorm. Others are drawn to the much less shady characters like Quieta, Cicada, and Barbata and come to the conclusion that while their actions up to the Moon Arc were monstrous, the Lunarians as a whole were motivated out of desperation and point to their willingness to plan with Phos and assist them as proof of inherently good natures. Some even considered Sensei the true villain of the story due to his seeming willingness to let gems die rather than praying for the Lunarians, though this has been mitigated somewhat as Sensei has been shown to not be unwilling, but unable to pray for them. Then it was ultimately revealed that the Lunarians' motive would also ensure the complete extinction of the human race, without counseling with anyone else of the other species until centuries after the plan was already in motion, making any sympathy for them fly straight out the window.
  • The marriage of Aechmea and Cairngorm. As noted in the No Yay section, some find the relationship predatory and very imbalanced, considering the circumstances on which it began (Cairngorm being emotionally vulnerable from being Antarc and Ghost's Replacement Goldfish) and how naive Cairngorm was concerning the role and meaning of a marriage. On the other hand, a significant group of fans across both sides of the sea look at the pairing as a genuine and loving partnership, since Aechmea's feelings for Cairngorm appear to have no ulterior motives and the Gem eventually grows to feel the same for him. The fact that Cairngorm finally seems to get over their imposter syndrome while with Aechmea comes up as a debate point for this ship, with many debating on if it was actually resolved rather than pushed aside.
• Catharsis Factor: For those that felt Phos was wrongfully betrayed by the rest of the Lustrous after the Moon Arc and in general think low of Phos in the early series, they found a lot of joy between Chapters 89 and 94, where Phos wholesale overpowers most of the Earth Gem opposition and finally avenges their betrayal by smashing Cinnabar to bits, absorbing their mercury and becoming a human. Although this is quickly recinded when everything Phos did only ended up isolating themself on Earth while Aechmea reaps the rewards on the Moon.
• Ending Fatigue: The chapters after the former human species are prayed away are a very long epilogue full of little action and long exposition dumps with multiple confusing time skips. The general consensus is most of the epilogue is Padding that could have been condensed into a shorter time span, but is instead being dragged out to fit into 108 chapters, a sentiment not helped by the multiple long hiatus the series went on during this time.
• Ensemble Dark Horse:
  • The Diamonds are immensely popular in the fandom. Bort, with their serious fighting mindset and gap moe for Cuteness Proximity; Diamond themself for their cute looks and sweet personality; Yellow Diamond for their ancient and mysterious older brother characterization. The anime only amplified it; after episode 2 went on air, Pixiv, Twitter, and other similar sites were filled to the brim with Dia fanart. There are even those in the fandom that say they should have been the protagonist.
  • On /a/ at least, Jade got a lot of positive press for their fun facial expressions throughout the early episodes of the anime, propping them up as a mascot of sorts.
  • Padparadscha is quite popular despite their limited screentime. Probably helps that they're a Cool Big Bro to Phos, their existence gives depth to Rutile's character, and they have pretty, long, flowy hair. They're also extremely Bishounen, which the female viewer/readership tends to like. Notably, Padparadscha is the one gem who has never betrayed Phos in any way and has instead saved them multiple times, which also wins them fans.
  • Ventricosus has quite a following, probably due to her unique design, her hilarious antics as a slug, her famous line about her "especially rare and valued parts," and her role in kickstarting the plot as something of a Knight of Cerebus.
  • Aculeatus has even less screentime than his sister but gained a lot of fans for his cool design and his incredibly one-sided fight with the Lunarians.
  • Blue Zoisite is fairly popular despite being a Posthumous Character that's only briefly mentioned in the Manga and only depicted in the official art book. After the release of the art book, they gained a fanbase as well as a ton of fanart, with people even wishing they hadn't been killed off before the start of the manga's events. To a lesser degree, the same can be said for Chrysoberyl and Imperial Topaz who are depicted in the art book alongside them. Fortunately, thanks to Amethyst's Gem-To-Lunarian converter, they were brought Back from the Dead, and The Party At the End at least shows shades of their personality through interactions with their lover Ladra.
• Estrogen Brigade: It says something when this seinen work has a huge female fanbase. Even the advertisements for the anime adaptation came from magazines like PASH, which have predominantly female readerships.
• Everyone Is Jesus in Purgatory: No serious discussion of this manga is complete without tying the characters to different aspects of Buddhism, its figures, and related myths. Just what each character, item, and event represents is hotly debated though.
• Fandom-Enraging Misconception:
  • The gems aren't male or female. The gems are sexless, androgynous but "X pronouns" should be used for them. This is only an issue in the English speaking fanbase and it's a pretty split debate.
  • Illogically claiming that the gems are girls just because they have female voice actors despite the fact that a male character could very well have a female voice actor and still be male. ^note There’s also the fact that the gems, despite all having female voice actors, have different intonations of their voices with some gems taking on deeper more masculine voices and speech patterns, similar to personas female voice actors take on for the male characters that they plan when the Cross-Dressing Voices trope applies.
  • Saying/Implying that Houseki no Kuni was heavily inspired by or that the mangaka copied Steven Universe, or vice versa for that matter. You will be reminded by a fan that Houseki no Kuni came first and it's a bunch of happy coincidences that the works are superficially similar. Heck, even pointing out the minor, perhaps coincidental similarities between the two series is enough to get some fans going on about how the shows shouldn't be compared just because they're both gem-based works.
• Fan Myopia: While Phos as a character has suffered a lot and the story seems determined to make them keep suffering on their road to maturity, a lot of their failings have been ignored by the fandom. The Gems on Earth were always wary of the Lunarians, so Phos' proposition to hand Sensei (their leader and father figure) over to them and their secretly taking other Gems to the Moon would be seen as irrational. Furthermore, while the gems do take down Phos and scatter their pieces, they only do this when Phos' command to pray disintegrates the holding cell they're in and when they use their gold, which was used as a weapon the last time they saw each other. Similarly, Cinnabar giving the suggestion to scatter Phos could be seen as more merciful compared to Rutile wanting to just throw Phos in the ocean, and burying them keeps them from coming back to the Lunarians.
• Fan Nickname:
  • Crazy Diamond for Bort.
  • Cinnamon for Cinnabar.
  • Phos post getting Lapis' head is usually called "LaPhos".
  • Cairngorm gets all sorts of silly nicknames to mispronounce their name. "Craig" is most common. "Cringeworm" or "Mooncake" became popular alternate nicknames for Cairngorm after they get their eyes replaced, at least on 4chan threads. "Karen" also became popular.
  • "The Rockbros" for the rock species that appeared after all the humanity subspecies were prayed away, for being friendly and mellow.
  • The First Machine is called "Brongo", a portmanteau of Brother (the name the Lunarians use for him) and Kongo (his younger brother and their mother Ayumu's second creation).
• Fan-Preferred Couple: For those who don't pair Cinnabar with Phos, Bort/Cinnabar became a popular alternative given that Bort actively tries to bring Cinnabar into the group following Sensei's demotion.
• Fandom Rivalry/Friendly Fandoms: As one would expect, some fans of this work and of Steven Universe don't get along, and tend to argue about which gem-based work is the better one, but there are also fans of both that think both are good in their own right. Either way it's more likely than not for fans of this show to also have some kind of opinion about Steven Universe, and vice versa.
  • On the Friendly Fandoms side, it has a bit of a fandom overlap with Touken Ranbu, oddly enough. There has been a steady flow of the Touken Danshi being drawn as gems on Pixiv and Twitter because of it.
• Fandom-Specific Plot: Though not as popular to do, like in the Steven Universe fandom, it's a thing to create your gem character. Presumably, the only reasons why this isn't as common in the Houseki no Kuni fanbase is because of how restrictive the rules of the universe are in comparison to those of Steven Universe. For example, the series starts off with 28 gems^note  not counting all of the gems that were taken to the moon prior to the start of the series all living together and that it's specifically stated by a character that gems like Phos and the others are rarely born, hence why Phos is one of the youngest despite being 299 years old at the start. Unlike in Houseki No Kuni, in Steven Universe, it was left open-ended early on as to whether or not there were more gems than just the Crystal Gem quartet, thus leaving more room for fan character creation.
• Fanwork-Only Fans: Houseki no Kuni unsurprisingly has a lot of these. Some non-fans admit to not caring much about the show/manga and only are here for the fan-created content such as the high quality fanart.
• Foe Yay Shipping: Post the departure to the Moon, many fans have accepted many pairings for Aechmea, notably Aechmea/Sensei, Aechmea/Phos, and Aechmea/Cairngorm, despite him being their designated enemy as the ruler of the Lunarians.
• Genius Bonus:
  • Phos being given gold and platinum alloys to replace their arms is a reference to kintsukuroi, the Japanese art of repairing broken pottery (particularly those with cracks) with lacquer of gold, silver, or platinum. The piece is considered more beautiful afterwards, as a broken history is seen as beautiful in Japanese culture; true beauty is struggle.
  • Many of the Buddhist references throughout the series, which only become more prevelant as the series' endgame approaches.
  • Characters' settings are based on their Mohs Hardness scale, tenacity, Crystal structure, classification in Mineralogy, mineral association, uses, natural occurrences, etc:
    • Bort is usually a industrial diamond and it is the remain of mining and processing diamond. So in the story, Diamond is Bort's older sibling.
    • The team of Benitoite and Neptunite——Both are associating minerals.
    • The team of Zircon and Yellow Diamond——Polished zircon and yellow diamond in jewelry always get confused.
    • The team of Morganite and Goshenite——Both are beryls and have names end in "-nite".
    • The team of Alexandrite and Chrysoberyl——Alexandrite is a variation of chrysoberyl.
    • The team of Peridot and Blue Zoisite——When zoisite was first discovered, it was mistakenly considered peridot.
    • The team of Sphene and Peridot——Green sphene look similar to peridot.
    • The team of Red Beryl and Aquamarine——They are the red and blue beryl variations.
    • The twin Amethysts' names,84 and 33, are from the The Japan Law, which implies that the c-axis of two crystals meet at an angle of 84°33', with two of the m prism faces of both crystals being parallel, so the twinning crystals will perform a heart shape.
    • Jade is one of the minerals which has the strongest tenacity while Euclase's is the weakest. In story they are the secretary group.
    • The crystal of Antarcticite in the show is sharp and thin. This is for it's crystal system is trigonal.
    • The gold block that trapped Phos' arms is the cubic form of a native gold crystal.
    • The design of Rutile's hair referenced the tetragonal crystal system of rutile.
    • Rutile has been widely used in industrial work. So their job is to fix and cure the broken gems.
    • Obsidian was used to make weapons in the Stone Age. So their job is to produce swords.
    • Antarcticite mentioned that the floating ice is also minerals. This is actually true.
    • Cinnabar's mercury once directly in contact with the other gems will become opaque. This is because mercury can infiltrate some other materials.
    • Heliodor's name means "the gift from the sun", while the Moon people like to appear in sunlight...So they were taken away.
    • The librarian Ghost Quartz and Lapis Lazuli are both the combination of several minerals and rocks.
• Harsher in Hindsight:
  • After Phos gets Lapis' head, Cairngorm and Red Beryl are somewhat relieved to see that Phos acts like the same Gem they've always been, with Cairngorm commenting that they thought Lapis would have overwritten their personality. As of the Moon arc, you could say there's more Lapis than Phos in that body now, especially with how methodical and manipulative they act.
  • One of the lines in the first opening is "dreams that repeat, changing form, are the only things keeping me connected to here". Phos is suffering from identity & memory loss because they are literally losing their way every time they lose a part of their body and replaces it with someone else's.
  • Cairngorm's assertion that they don't want to go to the Moon and their terrified expression upon entering the Moon craft is much harsher after The Reveal that Cairngorm was being mind controlled into obeying Phos and had no choice in whether they agreed or not.
  • Any time Rutile mentions how much they devote their time to Padparascha's recovery, given how badly the gem snaps when Pad is taken to the Moon. For that matter, Padparascha themselves worrying about what might happen when Rutile can't work on them anymore.
  • In Steven Universe: The Movie, a Gem named Spinel attempted to destroy earth after being abandoned by Pink Diamond for 6000 years. In the manga, Phos had been buried and forgotten for 220 years. By the time they woke up, the only wish they had left was a rage fueled desire for Sensei to pray (which, unbeknownst to Phos, would end up killing every humanoid). They even vowed to turn all Gems into dust when the prayer failed in chapter 82.
  • Diamond's comment of being able to "look at [Bort] more fondly" after being separated from the Gem in Chapter 25 turns into this after the Moon arc—by the time Dia and Bort are fully separated, nearly all traces of lingering affection from the former to the latter are gone, with only seething hatred and an unhealthy obsession remaining.
  • Variegatus tells Phos that she wants her sect of the Admirabilis to go to the Moon one day, and promises Phos that they'll become advanced enough to do so. Not only do the Earth Admirabilis devolve to match the rapidly depleting food levels, but the ones with enough sapience do get to go the Moon... but only on Lunarian terms, and certainly not in the service of the figure they deified.
• Hilarious in Hindsight:
  • In what could possibly be considered a New Tens equivalent to Dennis the Menace, it's kind of fascinating that in about a year's difference Steven Universe became a full-fledged series, given both series' more-or-less focus on humanoid, sexless gems in some form. Heck, in the first volume of the official English translation for the manga, Kodansha took advantage of this by applying the caption on the back cover of "An elegant new action manga for fans of Steven Universe!" It should be noticed that this was eventually removed due to fandom backlash due to the stigma of comparing the two series.
  • Some of the characters in Steven Universe and Houseki no Kuni share similar traits, such as:
    • A yellow Zircon is associated with Yellow Diamond.
    • A big deal is made out of there being multiple Amethysts.
    • Padparadscha and Rutile are partnered with each other.
    • Alexandrite is a berserker.
    • Both currently known Tourmalines are based off of the Watermelon Tourmaline.
    • Peridot is The Smart Guy/The Stoic but is revealed to be Not So Above It All.
    • A quartz is "destroyed", but a new quartz is born from their remains (Rose Quartz^note pregnant with Steven/Ghost Quartz^note a type of smoky quartz, formed around Cairngorm, Steven^note inherits his mother's gemstone/Cairngorm^note once Ghost Quartz is chipped away, they are freed).
    • Both series have a Ruby and a Sapphire, however the Ruby and Sapphire of Houseki no Kuni are not prominent as they are being held captive on the moon, only to be shown in Yellow Diamond's flashback.
    • There are multiple Diamonds, including a Yellow Diamond. Steven Universe has a regular/White Diamond, Blue Diamond, Pink Diamond, and Yellow Diamond, while Houseki no Kuni so far has a regular Diamond, Bort^note imperfect diamond, and Yellow Diamond. There was a Green Diamond and a Red Diamond, but they're as good as gone by the present day.
    • Lapis Lazuli is a prominent character later on in the series, and both, while on the side of the protagonists, are somewhat morally scrupulous. Lapis of Houseki no Kuni is manipulative, while Lapis of Steven Universe was vengeful and later avoided getting involved in problems.
    • Both have Fandom Enraging Misconceptions about the genders of the gems.
    • Both have a mysterious history that make the actions of the antagonists look more justified and question the goodness of the protagonists' role-model.
    • They both have a Cairngorm/Smoky Quartz, who is a figure with very huge insecurities about themselves and their role in life.
    • Interestingly, Ventricosus lovingly refers to Dia as "My Diamond" in full English, where in SU this is a formal address to any one of the Diamond rulers of Homeworld.
  • Kodansha's promotion with Tasaki to create jewelry based on the individual Lustrous to promote the anime can come off as this given the context of the story as well as the fact both the Lustrous and the Lunarians are distant evolutions of the human race. Even later in the story, it doubly becomes hilarious after the Lustrous themselves end up making jewelry from their old bodies after becoming Lunarians.
  • The French translation started calling Sensei "Vajra" long before his true name was revealed in Chapter 65: Vajra Mahametta Ratana Ksitigarbha. Justified, as the term Kongou (金剛) was coined to translate Vajra in its original Buddhist context.
• I Knew It!:
  • Prayer involving not just Lunarian destruction, but also involving the Lustrous was a commonly held theory before its reveal in Chapter 80. There was also a lot of speculation over Sensei holding off on it not out of duty, but of love for the Gems he raised.
  • Right from the moment Aechmea introduces himself by destroying a fake piece of Antarcticite where Phos could see, fans had been predicting that he'd been manipulating Phos for years prior to their encounter on the Moon. Nobody was able to predict the scale of his plans though.
• Incest Yay Shipping: As seen with Fan-Preferred Couple above, Not a lot of people seem to have an issue with shipping Aculeatus and Ventricosus despite the fact that they're siblings. Shipping the gems could possibly be seen as this as well, considering the fact the gems consider themselves to be "brothers".
• Jerkass Woobie: The Moon People are eventually revealed to be this. They are the tainted souls of humans left behind when humanity collectively Ascended to a Higher Plane of Existence; as their Prince describes them, they are all that's left of those people "so pathetic that not even a single other would pray for them". To make matters worse, Sensei, who was designed by one of the last humans to pray for them and purify them of their sins so that they could move on, ended up suffering a glitch in his programming and retreated to Earth to take care of the Gems instead, leaving the Moon People stuck in an eternal purgatory. They've tried to get his attention constantly so he can allow them to pass on, but his unwillingness to do anything has forced their hand into continuously more drastic measures. It gets worse in later chapters; the Lunarians that remain were arbitrarily imprisoned on the furthest moon due to having slightly higher percentages of the souls of criminals than other Lunarians. Unable to receive Adamant's salvation, they tore at each other and melded together in different forms out of sheer despair until Aechmea took pity on them and led them with the mission of getting them into the afterlife at any cost.
• Launcher of a Thousand Ships: Phos. The most obvious and popular ships are Phos/Cinnabar and Phos/Antarc, but there are also shippers for Phos/Cairngorm, Phos/Lapis, Phos/Sensei, and so on.
• LGBT Fanbase: The gems are a race of genderless beings with No Biological Sex, which has naturally attracted quite a lot of nonbinary fans to the series.
• Memetic Mutation:
  • Calling Yellow Diamond "JauJau"(Pronounced "Jojo")^note Yellow's name was translated to "JauJau" in the official French release of the manga ("Yellow" -> "Yellow-Yellow" -> "Jaune-Jaune" -> "JauJau")., even in non-French communities.
  • A version of the comparison chart, "What I expected vs. What I got", with most people have gone into the anime expecting it to be a complete Magical Girl series, Moe series (ie. K-On!) and/or just like Steven Universe, only to find themselves comparing it to NieR: Automata.
  • Phos noises ^Explanation A carryover from Tomoyo Kurosawa's (Phos's VA) other role from Sound! Euphonium, the fans have also taken note of the obscure little noises Phos would make at least once in every episode.
• Memetic Psychopath: There is a joke theory that Red Diamond was actually a psychotic and violent gem on 4chan that became widely picked up.
• Moe: Quite a few gems qualify for the trope, especially Dia and Phos. Cinnabar can definitely be considered one in the original meaning of the word.
• No Yay: For a lot of the Western fandom and even some of the gems themselves, Aechmea/Cairngorm is this, with that part of the fandom agreeing that their relationship is creepy due to Aechmea’s demeanor, their power imbalance and the suspicion that Aechmea is only using Cairngorm for his own personal gain. Their wedding led to a lot of Squick reactions. This might be intentional.
• One True Pairing:
  • Padparadscha/Rutile has a decent following, as Padparadsha is just about the only thing that can make Rutile drop their usual snark.
  • Phos ships aside, Diamond/Bort is one of, if not the most, popular of the ships, for obvious reasons.
  • Ventricosus/Aculeatus is also fairly popular likely due to both of the characters Ensemble Dark Horse status' and to it heavily being implied to have become canon.
• Rewatch Bonus: All of Cairngorm's behavior towards Phos becomes much more interesting when you view it through the lens of Ghost's inclusions subtly pushing Cairngorm into Undying Loyalty. Particularly when their eyes glint as they offer their own head to fix a decapitated Phos or they glint again when Cairngorm insists that they do not want to go to the moon yet they follow Phos anyways. However, their denial of total participation completely flies in the face of everything they do and say inside of Ghost, making the situation rather ambiguous.
• Romantic Plot Tumor: Aechmea and Cairngorm's relationship is criticized by a great deal of the fandom who lament that so much time is spent on it in the Moon arc. That Cairngorm's characterization changed so much as a result of it does not help matters.
• The Scrappy: Cairngorm after the Moon arc has become one. While the gem was once popular, the personality changes they went through as a result of this arc grate heavily on the fandom and have earned them dismissive nicknames like "Mooncake" and "Karen" due to their abandonment of Phos when Phos needed them most in favour of the very untrustworthy Aechmea. Their appearances after the second time skip have also done nothing to endear readers to them, seeing as they know the gems will all die if Sensei prays yet are keeping that information to themselves.
• Ship Mates: People that like Lunarian/Gem pairings will often pair Barbata and either Phos or Amethyst 84 together to compliment Aechmea and Cairngorm.
• Ships That Pass in the Night: Cairngorm/Antarc has a considerably sized following despite that the fact that they have no onscreen interactions with each other. It could be explained that the characters have some relevance to each other due to Phos seeing Antarc in Cairngorm and them supposedly looking similar, however. Though the ship has slightly more basis later in the series, since Antarc and Welegato/Cairngorm become close friends after becoming Lunarians.
• Spiritual Antithesis: Western readers consider it to be one to Steven Universe. Aside from the Eastern/Western cultural differences, the two went in vastly different directions; whereas the Crystal Gems live on a modern Earth teeming with humans and their presence playing an integral role in the plot, the Gems of Houseki live on an Earth devoid of humans in the distant future, with their interactions with each other and the Lunarians being the main focus and were in fact evolved from humans. On a more physical level, while both are sexless, the Steven Universe Gems are Hard Light projections of their gemstones that use female pronouns, while the Houseki no Kuni Gems are composed of the minerals themselves and default to male.^note The Gems use gender neutral pronouns in the English release "Shattering" a gem in the former will essentially kill them completely, while in the latter they can be repaired with other minerals and strengthened so long as enough pieces are found. Their closest equivalent to "shattering", however, is being ground into moon dust. Unlike Steven Universe, two given gems can't fuse; their memories might, but depending on the will of the gem their personality will swing toward the gem whose parts were augmented into them rather than take on a new personality.
• Squick: The Prince/Cairngorm to some, due to the imbalanced nature of their relationship, how abrupt it was and due to Aechmea's shady nature.
  • Also for a lot of fans, their wedding kiss.
• They Changed It, Now It Sucks!: The English localized name sparks ire from some fans because of its supposed flowery nature. The literal translation, Kingdom of Gems, got the point across in a simple manner compared to Land of the Lustrous. Other localization changes (such as using "this gem/ that gem" in the English translation or using xe pronouns in the German translation) are also hotly debated against those that preferred the Lustrous using masculine Japanese language.
• They Wasted a Perfectly Good Plot:
  • The Admiriabilis, being one of the three main races, hardly get anything in the story despite two of its members playing critical roles in Phos' development. Any opportunity to expand on their culture and attachment to Phos is deliberately thwarted, as their culture goes by much faster than the other two races and their intelligence gets bred out after hundreds of years, both deliberately in the Moon Admiirabilis' case and as a result of evolution in the Earth Admirabilis' case. The latter case is even worse, since the Lunarians also take the last remaining sapient faction to the Moon. The last mention the race gets at all is in The Party At the End, in which Bort states that they've bred them back out of endangered species numbers and got them to agree to the oblivion plan.
  • The Gems reacting to their Lunarian conversion was always a topic of interest, with many fans wondering what would happen when they realize they've just been turned into their millenia-old enemy, what Gems who'd lost their partners would say when they see them alive again, or what Cairngorm/Welegato and Ghost would say to each other after all this time. Apparently, none of them objected, and the next time we see the Gems and Lunarians all of them have completely settled in. Ghost and Welegato's conversation as detailed in the Volume 12 artbook was also summarized as Ghost admitting they controlled Welegato, and Welegato forgiving them, all of which took place offscreen.
  • Initially, it was brought up that praying for all of the Lunarians at once would take the other main species out as collateral, which is part of Sensei's malfunctioning state. When the time comes, this is sidestepped by the Lunarians getting the other species to convert into theirs, as well as agree to getting prayed away in between time skips.
• Too Bleak, Stopped Caring: The later parts of the series have quite a few fans expressing dissatisfaction with the way the story shaped up. Although it was to be expected that resolving the Lunarian conflict wouldn't be easy, the fact that Phos keeps trying and failing to reach their goals, the increasing Black-and-Grey Morality of the Lustrous and the Lunarians, and especially the fact that Phos has very few allies on any side, with even that number decreasing as the conflict rolls on make it seem like an endless suffering festival at Phos' expense.
• Too Cool to Live: Antarcticite only lasted through Phos' 300th Winter, but they certainly made an impression on the readers. Competent, encouraging, mysterious, and one of Phos' first real mentor figures in the story besides Sensei, Antarc was truly a huge force in the story despite how little time they were present for it.
• Ugly Cute: Red Diamond's uncut form was angular, misshapen, and had hollow holes where their eyes should be, but their childlike innocence and growing pains before being reshaped made them downright adorable.
• Unintentionally Unsympathetic: Both factions of the Lustrous, after the Moon Arc.
  • For the Earth Gems: while it is true that the Lustrous wouldn't be so trusting of Phos after they brought a fraction of their remaining numbers to the Moon, which has been the source of their problems for millennia, some fans think that their predicament is their own fault. They don't question Sensei or their circumstances (and when they do, they put it past them), and when they received proof that the Lunarians aren't doing anything to the ones Phos took they still attack the Night Raid crew. These fans are especially unforgiving of Bort and Cinnabar, the former for remaining adamant on their distrust of anything Lunarian and the latter for having every chance to confirm Phos' claims but choosing not to, on top of being the one to suggest shattering and separating Phos. When Phos returns to Earth, both were struck by Karmic Death, especially Cinnabar.
  • For the Moon Gems: None of them showed a lot of concern for Phos when they were hidden away and when they failed during the Night Raid, instead focusing on their own problems. With the exception of Yellow and Padparadscha, it made the Moon Gems look ungrateful to Phos when they were the one who introduced them to Lunarian society in the first place.
• Unnecessary Makeover: Some fans really miss Cairngorm pre-Moon, feeling like their new look and attitude after the event was a downgrade from their blunt, more masculine design.
• Villain Decay: The moon people, who were initially presented as malicious and mysterious beings before the moon arc and then over time become less so and take on more Affably Evil but still somewhat shady personas due to their Woobie status. Aechmea gets hit the hardest with this when Cairngorm is involved.
• Viewer Gender Confusion: Because the Gems are presented as androgynous, many fans argue over whether they can be seen as more masculine or more feminine, but a lot of the fanbase's opinion leans towards them being considered feminine with a handful of exceptions. ^note  Cairngorm pre-marriage, Bort (To some, especially post haircut), Yellow Diamond, Old Morganite, Antarticite, Padparadscha, Peridot, Neptunite (if you ignore the hair style), Jade (helped by the way they speak), Goshenite, Yellow Zircon and occasionally Post Winter/Post haircut Lapis-Phos. There are those who categorize Benitotite as more masculine if they aren't the ones who say that physically they look more tomboyish. Cinnabar is debatable. A few of the gems that were taken to the moon, namely Blue Zoisite, Chrysoberyl and Imperial Topaz, appear to be fairly masculine in appearance as well if the official art book depicting them is any indication. It's usually agreed upon that Kongou-sensei is undoubtedly meant to be seen as a man due to having the appearance of a (male) Buddhist monk and having a male voice actor in an otherwise all female voice acted cast; however, it should be noted that the gender of the voice actors doesn't determine the gender of the character being played due to the Cross-Dressing Voices trope. ^note for example, Aculeatus is also voiced by a female voice actor despite the fact that he is also meant to be seen as male due him being the brother and eventually mate of his sister Ventricosus. Some of the gems despite being voiced by female voice actors have distinctly more masculine sounding voices, further muddying the debate and adding more ideas to discuss.
  • Regardless of where you stand on whether the gems are meant to be viewed as masculine or feminine, In the series' native language, a number of them frequently use the masculine form of " I "^note  " Boku/Ore " , refer to each other as " he/him "^note  Kare is the Japanese terms for he/him and use male familiar terms when addressing their siblings^note  For Elder Gems: Oniisama, Niisama and Aniki. For younger gems: Otouto. However, gender has never been brought up in the show. Considering Phos' amusing confusion about Ventricosus' body, it's possible that most gems have no concept of physical sex characteristics, and thus nothing from which to derive the concept of "gender" from. It's most likely that their genders are meant to be left up to interpretation.
  • Pretty much confirmed by Word of God in an official interview with Haruko Ichikawa herself in which she states that the setting the gems live in is without gender. In the interview, she states that the top half of the gems are male (hence their flat chests) and their lower half female (the hips), reinforcing that their bodies are androgynous in appearance. She states that for Diamond's design she merely thought "What is cute?" when designing them, implying that when she designed the gems, no particular genders were in mind. While this doesn't necessarily mean the usage of male pronouns and male familial terms is wrong as it is what is used for them by her, it only furthers the point that the gems aren't male or female. They're merely androgynous beings whose "genders" are left to be interpreted by the reader.
  • The concept of gems having no gender is Lampshaded in the manga, with Phos' confusion looking at Ventricoscus' breasts, the Moon people calling Phos a "crystal lady" and Cairngorm being referred to as the Moon Princess. Both terms in the two latter scenarios confuse the respective gems and Cairngorm flat out takes "Princess" as their new name for a while before being renamed Welegato.
• Visual Effects of Awesome: The Anime in its entirety is viewed as this by fans, non-fans and Anime reviewers alike, being held up as one of, if not the best CGI anime to date.
• What Do You Mean, It's Not for Little Girls?: With its colorful covers and characters, androgynous cast and gemstone-theme, you would be forgiven for thinking of it as a Shoujo at first sight. However upon getting into it, you'll quickly realize it's not. It's a Seinen, and for very good reasons.
• The Woobie:
  • Phos, turning into an Iron Woobie by the end of the story. They're a young Lustrous at 300 years old who is seen as useless by their peers, and in a relatively short amount of time they've lost his legs and arms, part of their memory, a fellow Lustrous and partner in Antarticite, and gains serious PTSD from it all. By the time they managed to control his new gold arms, Phos is a shell of their former self, and is more somber as a result.
  • Cinnabar's isolation is just heartbreaking. Because their body contains a dangerous metal in mercury, everything around them starts to die and other Gems can't touch them for fear of breakage. Most of the series has them on night duty, alone, watching for Lunarians that never come in the evening and hoping that they'd take them away one day. And the one person who cared enough to try and reach out, Phos, only sees them occasionally and becomes more and more different every time they meet. It's clear that Kongou-sensei feels terrible about it, but with Cinnabar's condition there's not much Sensei can do.
  • Yellow Diamond is seen as one as well. They've lived long enough to have multiple long-term partners, and has lost all of them save for Zircon. Being the oldest of the current group of Gems, they've also become very world-weary, lamenting that they've long forgotten what their original aspirations were and even joking about being put into a Deep Sleep like Pad is in.
  • Stoic Woobie: And then there's Kongou-sensei himself. Built to help purify the mutated and stranded souls of Humanity, Sensei just stopped doing his job and tended to the Gems instead. It's heavily implied that it's an internal problem with Sensei, but nobody can fix it because he's virtually indestructable and therefore can't be looked at. He clearly loves them, and even if he's not terribly expressive he does show his affection in other ways. This is exactly why the Lunarians try to take the Gems; in part, to ask of their cooperation in getting Sensei back on track, and also to give him a scathing reminder of his duty by pulverizing his beloved Gems and scattering their remains over the moon. And he still feels terrible about every single one of them.
• Woobie Species: Within the multiple time skips the series goes through things only ever get worse for the Admirabilis. At the start of the series they were all kidnapped save for one, while another is rescued and they manage to breed they are continuously kidnapped by the Lunarians, threatened for their shells, and later are purposefully taken and bred to lose their grandiose forms and intelligence so they will not be able to befriend Phos and prevent them from praying for the Lunarians.
• Woolseyism: Alex's preferred nickname gets a bit of a change. In the original, the gems call Alex Alex-san where Alex wants to be called Alex-chan, given that the "san" is already in Alex's name (romanized as Aleksusandoraito) and they want to be called by a cuter name (hence the -chan). The English release instead has everyone call them "Alex", where they want to be called "Alexi". To be fair though, Phos has referred to Alexandrite as 'Alexi' on several occasions in the original Japanese text as well as the Anime, though it seems they may be the only one.
  • The English fan translations refer to Kongou as "Adamant-sensei" instead of leaving it untranslated, unlike what happened with Cinnabar. As Kongou is the word for an indestructible material, Adamant was a good choice for a thematically similar name. Similarly, the French translation opted to name him "Master Vajra", which fits with the Buddhist imagery.^note And that was a really lucky break— see Hilarious in Hindsight above.

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