The Elder Sister-like One (姉なるもの, Ane Naru Mono: The Sister of the Woods with a Thousand Young in Japan) is a supernatural soft-horror story about a young neglected orphan named Yuu and his adoptive elder sister Chiyo, who just happens to be an eldritch horror from another universe. But, you know, in a good way.
Our story opens with Yuu, who after losing both his parents at a young age has been passed off from one unwilling relative to another. However, that all changes when Yuu's latest guardian suddenly falls into a coma, and Yuu discovers a mysterious basement under said relative's shed. After accidentally disturbing one of the markings on the floor, Yuu finds himself face to face with the beautiful but inhuman "demon" Shub-Niggurath, who offers to grant him a single wish in exchange for what he treasures most. Afraid for his life but also desperately lonely, the boy suddenly blurts out all he wants is a family and asks the inhuman abomination if she would be his big sister. So begins Yuu's happy, endless summer with his new sister "Chiyo", the kindest and most gentle horror this side of insanity.
The serial depicts the daily adventures of Yuu and Chiyo, for whom the simplest of activities have a tendency to become wanderings through eldritch territory. But, you know, in a good way.
Iida Pochi first created the story in the form of a series of hentai doujins, and then got to expand it into a non-hentai monthly serial while simultaneously continuing to publish said doujins. An OVA has been announced.
Compare to Nyaruko: Crawling with Love!, a series with a similar, albeit more slapstick premise with Nyarlathotep and other Mythos monsters.
This manga provides examples of:
- Absurd Cutting Power: In the second chapter, Chiyo forms a knife from her hair-tentacles and comically slices through the cutting board.
- Abusive Parents: Yuu's memories of his parents are of their kindness and love. However, since their death, he has been passed around from household to household by resentful relatives who bad-mouth him behind his back but within earshot. His maternal aunt even slapped him and blamed his parents' deaths on him during their funeral. His uncle Ryou was probably the kindest by simply ignoring him.
- Adaptational Nice Girl: Shub-Niggurath is one of the more benevolent deities in the Cthulhu Mythos but that's not saying much.note Here she's a very kind and loving being, whose emotions and motivations are far more human in nature.
- All Deaths Final: Both Chiyo and Haru have stated at different points that, while they may be Eldritch Abominations with incredible powers, Chiyo herself being in essence a goddess, the one thing they are completely incapable of doing, even when it's something they deeply, desperately want to, is bring people back from the dead. Ryou having this explained to him directly (meaning that even if Yuu didn't accidentally steal his wish, he still wouldn't have been able to see Yuu's mother again) is what makes him stop being outright antagonistic to the boy, resuming his original stance of simply disliking Yuu's Family Eye Resemblance to his mother. Unfortunately, it doesn't stop him from continuing to seek a way to bring Yuu's mother back for at least some time after, leading to Haru having to guard him from the many eldritch horrors his activities end up attracting as he blindly opens dimensional doors that allow access to creatures that find the scent of his desires delicious.
- Almost Kiss: Chiyo and Yuu nearly kiss in Chapter 3, but they get interrupted when the garden hose she was accidentally crimping with her hoof splashes them.
- Always a Bigger Fish: Haru makes short work of a malevolent Yōkai threatening Yuu in chapter 21 but Chiyo in turn quickly proves the stray dog is batting way, way out of her league toying with someone under the protection of Shub-Niggurath.
- Angry Guard Dog: Haru inserts herself into the role of guard dog when she moves in after Ryou regains his senses. Chiyo can only roll her eyes at the idea that Haru would think this is necessary in her presence. Haru counters that there may be creatures out there both not afraid of Chiyo and capable of getting past the threshold barrier she has set up, and furthermore Chiyo when it comes down to it would protect Yuu rather than Ryou.
- Arcadia: The story takes place in a very tranquil rural setting.
- Art Initiates Life: In one chapter while Yuu is doing his summer schoolwork, Chiyo passes the time practicing writing and drawing. Her drawings end up coming to life and running/crawling/slithering away, prompting Chiyo to try to catch them before Yuu notices.
- Art Shift: Constantly. Iida Pochi has a wide variety of drawing styles, but several of them come up frequently for strong emotions.
- Surprise - Whenever Chiyo or Yuu are comically surprised, their eyes become large circles and mouths become simple shapes, reminiscent of online ASCII art.
- Panic - Comically panicking, the two are animated in a stylish cross-over between the usual art and the comically surprised style.
- Vengeance - Chiyo goes into dark god vengeance mode, usually because she thinks someone has threatened Yuu, taking on her demon shape and forming a dark aura that fills the room.
- Loving - Chiyo's loving and nurturing mode, generally with heart-shaped pupils. Can happen with her human or demon form.
- Attractive Bent-Gender: Chiyo gets especially libidinous over Yuu when he crossdresses as a girl. It's implied that the dress up play they did in Chapter 22.75 was the first time this fetish awakened in her.
- Author Appeal: Iida Pochi likes drawing older, busty girls with younger boys just like her previous work for the art of the light novel Do You Love Your Mom and Her Two-Hit Multi-Target Attacks?.
- Berserk Button: Despite how minor it is, Chiyo does not like anyone other than Yuu calling her "big sis", as Haru finds out after teasing Chiyo and getting an entire Eldritch Ocean Abyss dropped on her head.
- The Big Damn Kiss: After several chapters of Ship Tease, Chapter 23 ends with the first aggressive kiss between Yuu and Chiyo, purely for love without any pretense of A Magic Contract Comes with a Kiss or other excuse, all for Chiyo to express that Yuu belongs to her after getting riled up by Haru.
- Bits of Me Keep Passing Out: Chiyo is rather alarmed at her first taste of pins-and-needles, and has to get Yuu to massage it out of her legs (complete with obligatory moaning).
- Bizarre Taste in Food:
- For their first meal together, Chiyo suggests that she "produce" and cook a placenta for her and Yuu's first meal. Whenever she was summoned by her worshippers in the past, this is what they served her, so she assumes it's a meal for special occasions. Yuu manages to push more conventional fare.
- In a volume 1 omake on YuuTube (get it?) Chiyo demonstrates how to cook various Lovecraftian horrors. Yuu cuts the lesson short in taste or terror, as Chiyo's meal is now obscured by pixelated censoring.
- Haru claims that Yuu has "a really tasty smell".
- Similarly, Chiyo freaks out Yuu by squeeing over the taste of his blood after kissing a wound better.
- Black Magic: Chiyo senses and manipulates black magic on a very fundamental level. Even her thoughts can cause inhuman conjurations.
- Blue-and-Orange Morality: As a Cthulhan Outer God, Chiyo genuinely doesn't understand certain things that are obvious to Yuu, like not killing certain people or creatures, or not eating certain foods.
- Bodyguarding a Badass: Chiyo is rather amused by Yuu's reaction to her summoning, but what gets her really intrigued in the boy is him (a human) attempting to protect her (a god) from an attacking monster.
- Boldly Coming: In the original doujins. Well, what else would you expect of the Anthropomorphic Personification of biological reproduction?
- But Now I Must Go: Ryou leaves the story looking for a fresh start in chapter 44, taking Haru with him.
- Call to Agriculture: Chapter 38 reveals Ryou works as a farmhand, with him introducing Yuu to the basics of the job.
- Chekhov's Gun: Yuu's fear towards dogs, first mentioned in ch. 6, comes back later in the series in an important way when Haru is introduced.
- Clingy Jealous Girl: Chiyo’s protectiveness of Yuu takes on a possessive bent once Haru comes into the picture, especially since Haru is not above making flirtatious passes at Yuu specifically to provoke a jealous reaction from Chiyo.
- Clothing Damage: Yuu tears his pants in chapter 39, prompting Haru to teach Chiyo how to sew.
- Continuity Drift: The uncle whose house Yuu lives in is initially established to be the cousin of Yuu’s mother, in a way that suggests he is purely a maternal uncle. Later chapters reveal that he is also the brother of Yuu’s father, without actually retconning away the part about him being cousins with Yuu’s mom, turning Yuu’s parents into Kissing Cousins and giving him a much closer blood relation to Yuu than what was first introduced.
- Covert Pervert: Chiyo harbors a strong lustful attraction to Yuu, though the manga takes place before she gets to indulge in her most lascivious desires with him, so it only occasionally slips through her "wholesome sister" demeanor. Yuu himself is also quite conscious of Chiyo as a beautiful woman, though he’s a bit better at keeping his dirtier thoughts to himself.
- Crazy Sane: When Yuu continues acting totally normal and genuinely smiles in response to Haru's observation that Chiyo will no doubt one day corrupt and warp the world itself for his sake, Haru notes that Yuu has already long since become perfectly fine... with being insane.
- Creating Life Is Unforeseen: Chiyo's moniker is well deserved, even her drawings can come to life without her intending it.
- Cute Little Fangs: Haru sports a pair of these. They hint at her demonic form, with a full set of monster fangs.
- Cute Monster Girl:
- Even in her tentacle haired, eyeball wearing demon form, Chiyo is still a far cry from ugly.
- Similarly, despite her oversized demonic claws and teeth, Haru is quite attractive.
- Darker and Edgier: The later manga chapters that delve into the background of Ryou’s past with Yuu’s parents take on a grimmer tone and explore the characters’ pains as well as play the cosmic horror straighter, compared to the rest of the series and the original doujins that focus more on good vibes and sweet moments.
- Dead Person Impersonation: Haru's human form is actually a copy of The Lost Lenore of Yuu's uncle Ryou, aka Yuu's dead mother as a teenager.
- Deal with the Devil: The primal creative force of Shub-Niggurath is released from dank runes in a foul basement and declares, "I will grant you what you wish for in exchange for what you value most." Terrified, Yuu heedlessly asks this unspeakable abomination for the unthinkable: "Please be my big sister!"
- Delicate and Sickly:
- A flashback shows Yuu's mother suffered some unspecified ailment that left her very frail and heavily reliant on an inhaler.
- Yuu himself seems prone to fainting spells.
- Did We Just Have Tea with Cthulhu?: Tea, cleaning, walks in the country. It's Slice of Life, after all.
- Did You Just Romance Cthulhu?: Yuu and Chiyo catch each others' hearts pretty quickly.
- Dramatic Irony: There are a few moments that play on the readers knowing the Foregone Conclusion that the doujin canonically takes place after the manga serialization, and what happens in it.
- Yuu is occasionally fearful of the prospect that his very life will end along with the peaceful days he enjoys with Chiyo once she decides to collect on his debt for the wish. While she does end up devouring him, it’s not the kind of devouring he expects…
- Chapter 25 ends with Haru commenting on how surprised she is that Yuu and Chiyo are innocent "siblings" to each other. Even discounting where that relationship ends up in the doujin, she is unaware that a few chapters prior, they shared The Big Damn Kiss after she left, and that neither of them were immune to Eating the Eye Candy and other ecchi antics even before she showed up.
- Aside from the doujin, Ryou’s intention to summon Shub-Niggurath to resurrect Yuu’s mom is only revealed to the reader several chapters after Chiyo already told Yuu that defying All Deaths Final is beyond her power.
- Dysfunction Junction: All four members of the major cast have some serious issues, whether it's because of bizarre moral perspectives and/or because they're carrying heavy baggage from their pasts.
- Ear Cleaning: Since this is common for elder sisters to perform on younger brothers, Chiyo insists on doing this for Yuu ...with her tentacles. Judging from his reactions, this is an incredibly intense sensation, much like having someone lick your entire ear canal.
- Eating the Eye Candy: From the moment they met, Yuu can’t stop appreciating how beautiful Chiyo appears to him, especially when she has an Innocent Fanservice Girl moment. The attraction is reciprocal; in Chapter 3, Chiyo’s heart gets racing at the sight of Yuu with his shirt off, and she practically drapes herself over him.
- Eldritch Abomination:
- Chiyo is Shub-Niggurath, one of the most powerful and ominous entities of the Cthulhu Mythos. She can warp reality, shapeshift at will, pull in monsters from another dimension to make a nutritious meal, and has little to no understanding of how humanity or our reality work.
- Later chapters add Haru, one of the eponymous hounds from The Hounds of Tindalos, who can shapeshift at will between a human girl, a "demonic" dog girl, and an undulating mass of random organs and tentacles. She can also slice Yōkai to ribbons with ease, despite her powers and alienness falling far below a "goddess" like Chiyo.
- Emotion Eater: According to Haru, the various eldritch monstrosities that plague the household are drawn to the desires of Ryou, who opened the doorways to them in his reckless pursuit of a way to resurrect Yuu’s mom.
- Eyes Are Mental: Chiyo's pupils tend to betray her inhuman nature, often looking like goat pupils.
- Eyes Do Not Belong There: In her demon form, Chiyo can have a necklace of eyeballs. They apparently work. As a rule of thumb, the more eyeballs she's wearing, the less human she is at that moment.
- When Chiyo first meets Yuu, she's optically festooned with a moderate necklace.
- Chapter 3 is after Chiyo agrees to be Yuu's elder sister, with nary an excess eyeball in sight when she takes her demon form.
- Chapter 17 has Chiyo going demon to protect Yuu, wearing a heavy wreath of eyes and talons dripping with ichor.
- Chapter 21, Chiyo confronts the demonic creature Haru and goes full-on demon: her tentacle-hair is like a midnight river, cruel talons form, and her cleavage is virtually frothing with eyeballs.
- Family Eye Resemblance: It's been mentioned a few times that Yuu shares his mother's eyes. It's something that seriously pisses Ryou off, as not only does it remind him of the fact that she's dead now, it's also a constant reminder that he lost her to his brother.
- Family Theme Naming: Invoked. When Shub-Niggurath forms a contract with Yuu to become his older sister, she chooses the human name Chiyo (meaning "a thousand nights") to complement his name (meaning "twilight").
- Fear of Thunder: Another of Yuu's fears.
- Fertile Feet: Chiyo being a fertility goddess, her powers sometimes overflow this way without her meaning to, like accidentally causing a watermelon plant to grow and mutate due to thinking too hard about watermelons.
- Flashback:
- The author likes to drop tantalizing hints about previous unhappy events in Yuu's and Chiyo's lives prior to the main story. Yuu has a recurring nightmare about people looking down on him and the strangeness of his actions. Chiyo has painful memories about a young woman rejecting her and her inhumanness, mentions that she can't undo death, and is intensely protective of Yuu's life. To date, neither has spoken of these memories to each other.
- We later get a Whole Episode Flashback involving Yuu's uncle Ryou, which details why he got into the occult (he was trying to bring back Yuu's mother/his cousin due to being in love with her) and how Haru came into his life (it was caused by Ryou backfiring in his efforts, which brought him face-to-face with Haru's true form. The fact he didn't instantly go insane intrigued her, to which she responded by taking on the appearance of Yuu's mother in an effort to grant his desire to see her again, since she lacks the power to revive the dead).
- Foregone Conclusion: Some chapters of the manga have Yuu bittersweetly contemplating how his peaceful days with Chiyo will not last forever, practically raising death flags about his expectation that she will eventually eat him to fulfill his end of the contract. Anyone familiar with the source material knows he has nothing to worry about, because Chiyo has something else in mind for payment.
- A Form You Are Comfortable With:
- Haru first shows herself to Ryou as a genuine, bonafide Eldritch Abomination of undulating tentacles, random organs and jagged teeth, before taking on her current appearance in order to allow him to retain his sanity and appeal to him in the form of the dead cousin he was in love with.
- Given Haru's example, it's heavily implied that even when she's at her most monstrous, this is also true of Chiyo, with her Humanoid Abomination appearance being the result of taking on a form similar to a human she knew in the distant past, in a conscious effort to avoid breaking the mind of whoever might summon her.
- Friend to All Living Things: After a black magic mutated rat invades the house and eats their snacks, Yuu still hopes that it'll escape into the wilderness where it won't be killed by humans.
- Hates Being Alone: After a life of neglect, Yuu's desperation for company and family that will actually love him drives his wish for an older sister.
- Healing Hands: Chiyo demonstrates the ability to heal wounds in chapter 7.
- Hell Hound: Chapter 21 introduces Haru, a self described "stray dog" implied to be one of the Hounds of Tindalos.
- Hot in Human Form: Chiyo is Shub-Niggurath and Haru is some kind of lesser Eldritch Abomination, but both take on the forms of beautiful human women, Chiyo becoming stunningly gorgeous and voluptuous with long, dark hair, and Haru becoming an attractive but more petite-figured blonde. Yuu finds Chiyo breathtakingly beautiful and has to struggle at times to keep seeing her as just his "big sis".
- Humanoid Abomination: Let's just say the whole thing brings a whole new meaning to the phrase 'Elder Sister'.
- Humans Through Alien Eyes: A volume 3 omake has Chiyo give a review on "YuuTube" about how she finds having a human form.
- Identical Stranger: Haru looks just like a younger version of Yuu's late mother. It's stated she took this form because of Ryou's unrequited love for the latter.
- Ignorance Is Bliss: Yuu never really asks Chiyo any questions about her eldritch background, likely trying not to disrupt their peaceful status quo.
- I Have Many Names: Chiyo has been referred to by a lot of names through the centuries: demon, evil goddess, the Black Goat of the Woods with a Thousand Young. After meeting Yuu, she adds angel, big sister, and Sister of the Woods with a Thousand Young to her list.
- I Just Want to Be Loved: Yuu and Chiyo's shared motivation. Yuu, an orphan who's been passed off from one unwilling relative to another, wants to have a family that cares for him. Chiyo, an Eldritch Abomination who ends up being hated or feared every time she gets summoned to our dimension, secretly wishes a human would accept rather than be horrified of her for a change.
- Incest Subtext: There is a lot of Ship Teasing between Chiyo and Yuu, though they technically aren't siblings in any real sense of the word (she's an Outer God who made a contract with him to act as his older sister rather than an actual relative, and acts more like his wife in practice despite naming their relationship as a sibling one). This isn't helped by the fact that the series was originally a hentai before it was picked up for serialization.
- Interspecies Romance: Boy meets Lovecraftian-avatar-of-the-concept-of-creation-itself, you've heard it a million times. Haru would like to have this with Ryou, but he’s only interested in Loving a Shadow at best.
- Journey to Find Oneself: Why Ryou ultimately decides to leave for parts unknown.
- Kissing Cousins: Yuu's parents are revealed to have been first cousins.
- Loophole Abuse: Yuu is bound by magical contract to give Chiyo that which he values most in exchange for his wish. Fortunately by the time payment is due, what he values most is his relationship with her, allowing Chiyo to fulfill the contract by simply "indulging" in his love.
- Lovecraft Lite: It's a Slice of Life story with the eponymous Eldritch Abomination taking the role of a big sister for a boy, and it's pretty touching.
- Love Triangle:
- Subverted when Haru joins the cast. Although she sometimes treats Yuu with a flirtatious affection, it’s clearly because Chiyo’s Clingy Jealous Girl reactions to it amuse her more than her having any real attraction to him, and Yuu makes it clear that Chiyo’s the only "sister" for him.
- Yuu's father and uncle were both in love with their cousin, Yuu's mother.
- Loving a Shadow: In an odd case where the "shadow" deliberately invokes this and uses it to keep said "love", Ryou and Haru have a peculiar relationship where Ryou hangs out with and displays a bit of affection towards Haru because she has the appearance of the dead woman he was in love with, and Haru accepts the false affection so that she can stick around the human she genuinely adores.
- A Magic Contract Comes with a Kiss:
- Chiyo seals the deal with Yuu this way, solemnly swearing to grant his wish without deviation.
- She also 'kisses it better' after magically healing a wound for Yuu.
- Make a Wish: Shub-Niggurath confronts Yuu and offers him a wish. Confronted with impending death, Yuu suddenly realizes that what he wants and needs more than even his life is family, specifically an older sister. It quickly becomes clear that this being takes wishes and contracts very seriously.
- Mayfly–December Romance: Unless she spirits him away to one of those strange aeons or something, Yuu is going to predecease Chiyo by an eternity.
- Monster Brother, Cutie Sister: A Gender-Inverted adoptive example, with Yuu being the incredibly sweet and adorably precious human brother, and Chiyo being the inhumanly beautiful and often terrifying monstrous Humanoid Abomination sister.
- Mother of a Thousand Young: Chiyo is the manga's version of the trope namer, Shub-Niggurath.
- Mundane Utility: Chiyo's tentacles have many abilities, forming hair, clothes, or unstoppably sharp knives and devouring black magic mutated rats. In the doujin she uses the ability to split herself in order to do chores faster ...and get into a Twin Threesome Fantasy.
- Necromantic: Yuu's uncle Ryou began delving into the occult to try to find a way to bring Yuu's mother back from the dead. It just ended up summoning Haru instead.
- The Needless: In Volume 6 Haru notes that beings like her and Chiyo don't really need to do anything if they want to simply keep existing (hence why she is never seen sleeping, for instance), but notes that living that way is exceedingly boring, so she has taken on many hobbies.
- Nipple and Dimed: It isn't until the third volume that Chiyo's breasts are drawn uncensored, and even then her nipples aren't rendered with full detail.
- Only Sane Man: Ryou (in the colloquial sense at least). He's the only member of the cast who doesn't react to the eldritch weirdness around him as an Unusually Uninteresting Sight.
- Public Domain Character:
- Chiyo is Shub-Niggurath from H. P. Lovecraft's Cthulhu Mythos.
- Haru bears certain similarities to both the Hounds of Tindalos and the Flutists that keep Azathoth asleep, also from the Cthulhu Mythos, though neither has been explicitly named as Chiyo has.
- Punny Title:
- The English title "Elder Sister Like One" can be read as referring to Chiyo's identity as Yuu's Adoptive Cool Big Sis or as an Eldritch Abomination.
- The Japanese title "姉なるもの / Ane Naru Mono" can be read as both "My Elder Sister" and "The Thing that Becomes My Elder Sister". The subtitle is similarly a play on Shub-Niggurath's title "The Black Goat of the Woods with a Thousand Young" in Lovecraft fiction.
- Puppy-Dog Eyes: Chiyo only relents to spare Haru's life in their first encounter after seeing Yuu's pleading expression.
- Raijū: Yuu brings up said thunder god during a lightning storm. Chiyo's image of gods being rather different than his, we're treated to pretty different mental pictures based on his description between the two.
- Romantic Runner-Up: Yuu's uncle Ryou was one to his brother, Yuu's father.
- Room Full of Crazy: In the first chapter, Yuu discovers a hidden room with unnaturally angled ceilings and walls, covered with eldritch symbols and reality-warping patterns, pungent with smells that foul the eyes and leave him dazed and confused. This forms a gateway to summon other beings into our world. Chiyo finds it messy and cleans it, removing its paranormal nature. Haru is stunned into speechlessness.
- Self-Censored Release: The Elephant in the Living Room is that the original story was a series of onee-shota (mature woman with adolescent boy) hentai doujins. However, the underlying relationship was so heartwarming that it was made into an all-ages monthly serial. Extensive Ship Teasing ensued. On the other hand, Pochi has continued to produce the H doujins even while working on the serial ...and author notes indicate that the doujins are canon to the manga and simply take place further down the timeline.
- Sensory Overload: A rare benevolent example from the original doujins, in which Chiyo is heavily implied to be gently overwhelming Yuu's mind with pleasures beyond ordinary human perception.
- Sex God: In the Cthulhu Mythos, Shub-Niggurath is the Anthropomorphic Personification of the event or act of creation, in particular the reproduction of biological life, making Chiyo a literal example. She proves her stripes as a metaphorical one in the doujins, as Yuu can attest.
- Shapeshifting:
- Chiyo switches between her human and demon form as easily as thought. Since her clothes are formed from her hair, she can also cosplay at the drop of a hat, generally as a mythological being.
- Haru is also shown to have originally been an undulating mass of eyes, organs and teeth before taking on her current form based on Ryou's Lost Lenore.
- Shout-Out:
- The Tsukada Shop that Yuu & Chiyo visit in Chapter 13 has an advertisement for Nuka-Cola.
- In Chapter 28.5, the pair of customers Haru serves in the soba shop are Kagami Hayato and Yashiro Kizuku.
- Chapter 36 starts with Haru and Chiyo browsing a fashion magazine that features the outfits of Iofi, Reine, Ollie and Anya. Fitting, as Iofi's collaborations with Pochi, the manga's artist, led to her being Reine's character designer. A few pages in the same chapter, Haru briefly dons the outfit of Pochi's very own "Pochimaru" VTuber avatar.
- The Sleepless: One chapter follows Haru through a Day in the Life, where we learn that in a single day she's a Triple Shifter, working in a grocers, a restaurant, and a flower store. This is followed by messing around with Chiyo and Yuu, then sitting up with Yuu's uncle all night. Does she ever sleep? It has yet to be seen.
- Slice of Life: Every chapter is a slice of Yuu's daily life with unspeakable horror reformed into the image of a loving older sister. Cooking, cleaning, going for walks, etc.
- Smashing Watermelons: Yuu and Chiyo play Suikawari in chapter 11.
- Smells Sexy: Yuu and Chiyo both find each other’s scent intoxicating. It leads to an Almost Kiss in Chapter 3, and Chapter 8 has Chiyo get so enraptured with her Perverted Sniffing of Yuu’s laundry that she falls asleep and leaves some chores unfinished.
- Spit-Trail Kiss:
- A trail connects Yuu and Chiyo’s mouths after she seals the contract with him in the first chapter.
- The Big Damn Kiss in Chapter 23 includes a panel of Yuu's face with a trail of saliva from his mouth.
- Statuesque Stunner: In Pochi's art featuring Chiyo and Mamako, the former is drawn about half a head taller. The hentai works state that she's 172 cmImperial in human form.
- Suck Out the Poison: Chiyo does this for Yuu to suck out the mosquito saliva from his bug bites (she's an Outer God, so she can actually do this). It backfires when she gets to a bite that he already treated with muhi, causing her to get a mouthful of foul-tasting medicine. So ends another episode of UST.
- Swarm of Rats: One of the many unpleasant results of someone in the past dabbling in black magic in the storehouse.
- Technically Naked Shapeshifter: All of Chiyo's clothes seem to be formed from her prehensile hair.
- Temporal Theme Naming: Yuu comes from "yuugure", meaning "twilight", so Shub-Niggurath chooses the name Chiyo, meaning "a thousand nights" to compliment Yuu's name.
- Textile Work Is Feminine: Chapter 39 has Haru teaching Chiyo to sew for Yuu.
- Thanks for the Mammary: Chiyo has Yuu check whether her human form has an accurate heartbeat the fun way in chapter 2.
- Too Many Mouths: Chiyo has a mouth in each palm when she's first summoned.
- Twin Threesome Fantasy: Happens twice in the hentai related works, where Chiyo becomes first two beings: her human nurturing form and demon dominating form. The second time is split between an angelic Chiyo who gently rewards and a demonic Chiyo who gently teases.
- Unresolved Sexual Tension: This pops up constantly between the two faux siblings. Chiyo is gorgeous in her human form, while her alien form seems to overwhelm Yuu's senses. In turn, she seems quite taken with Yuu's adolescent body. However, unlike the source material this is an all-ages story, so something always interrupts them before things get out of hand.
- Violently Protective Girlfriend: Chiyo does not take well to anything that threatens Yuu. Even a mosquito bite is enough to trigger full-on demonic vengeance. (Though in her defence, it's not like a human is that much stronger than a mosquito from her perspective, so she can't really be expected to understand the level of threat one poses.)
- Wound Licking: Chapter 7 has Yuu teach Chiyo about "kissing it better" when she gets a cut on her finger. She returns the favor when he bites the inside of his mouth, despite having already patched up the wound with her own magic beforehand.
- Wowing Cthulhu: In the first chapter, Yuu repeatedly leaves Chiyo drop-jaw astonished by his uniquely innocent behavior towards her.
- When she offers him a wish, he asks her if she's an angel. The tragically neglected orphan never had anyone ask what he wants before.
- He then wishes that this inhuman monstrosity become his sister, regardless of suspecting that the price will be his life.
- Next, the adolescent tries to protect the insanely powerful God of Evil from an attacking random monster. At this point, she seems to realize that she's dealing with someone incredible.
- Wrong Genre Savvy: If he were in a straight Cosmic Horror Story, Yuu's certainty that Chiyo's eventual price for his wish will be his life would be quite justified. Fortunately for him, the series is Lovecraft Lite, and a lewd one at that, where she actually ends up devouring him in an entirely different way.
- Yamato Nadeshiko: Chiyo's image of being Yuu's perfect older sister generally leads her into this role.
- You Cannot Grasp the True Form: Yuu frequently has to remind himself that no matter how she looks to him, Chiyo's true self is beyond human comprehension. More unusually for the trope, Haru claims that this works the other way too; just as a human cannot ever truly understand an outer god, such a god cannot ever truly understand what it is to be human.
- Youkai: An early chapter reveals that Yuu can see the supernatural. He badly upset relatives by reacting to and talking with things that no one else could see. This is part of why he was rejected by his remote family. Chiyo notes that the creatures exist on a different level of reality, and it's very unusual that Yuu is able to see them.
