Alternate Character Interpretation: Due to their calm demeanor about how history is protected despite losses, the interpretation of the Saniwa as hardened and apathetic rose around episode 4. Episode 5 got them a reputation as a "sword-breaker" type, since they worked Tonbokiri to cracking point and only pulled out when they were certain the boys were in an unwinnable situation.
Almost out of the starting gate, with how Horikawa is portrayed in this adaptation. Since he's been newly summoned and is taking some pointers from Izuminokami, some fans think their dynamic is reversed from that of the game and that Horikawa's relative inexperience takes away the knowledge and efficiency he had as the game version. Others are happy to see Horikawa with characterization that isn't completely centered around praising Izuminokami or being his bodyguard, and yet still others are calling him a retread of Hanamaru's portrayal of Yamatonokami Yasusada. The latter opinion only intensified after the events of the last few episodes.
This seems to have extended to a few of the other characters depicted in the Anime thus far, as people have pointed out that the character portrayals in Katsugeki seem to be a bit more tropey when compared to their original counterparts from the game as well as the other adaptations. By episode 3, however, the general reception of Horikawa has gotten better compared to how his characterization was received in the first episode.
Having another adaptation focused on some of The Shinsengumi swords. Hanamaru and the second and fifth musicals (Bakamatsu Tenrouden and Musubi no Hibiki, Hajimari no Ne) already focused on Kiyomitsu and Yasusada, and with the protagonists of Katsugeki being Izuminokami and Mutsunokami (sword of Sakamoto Ryouma, who was of opposite political opinion to the Shinsengumi), with Horikawa playing a major role in the story as well, some fans are sick of it altogether.
Somewhat alleviated with the full reveal of the first unit in episode 6 and their mission detailing that they will be visiting a time period that is not Bakamatsu (or related to the Shinsengumi at all, for that matter) thus giving focus to the first unit as a group rather than having the entirety of the series revolve around the second unit and by extension, the Shinsengumi swords, to the relief of the fans.
Tonbokiri's cracking in Episode 5. Either it's a well done scene that sets up the stakes the team will need to face in the future, or it's just cheap shock value and somewhat pointless because the person involved was an established, yet not terribly important character in both the story and in popularity, making him a safe choice for this kind of scene.
Continuity Lockout: Overlaps with Genius Bonus for non-Japanese viewers. A lot of the characters' personalities and relationshipsnote For example, Izuminokami's disdain for Mutsunokami, which is based off the conflict between the traditionalist Shinsengumi and the pro-modernization Ryoma Sakamoto are not explained outright and require a lot of familiarity with the games as well as Japanese history and the various figures who historically owned these swords. Not to mention the series takes place during the leadup to the Meiji Restoration and the premise is all about ensuring that Japanese history stays on track.
Ensemble Dark Horse: The Konnosukes from the other Units that appear in Episode 6, to the point where people in the fandom want to see them become canon to the game.
Epileptic Trees: It's common to theorize that at least one of the swords or the Saniwa has seen all of their comrades break before, given the bleak setting. One of the most likely candidates for this theory is Yagen, given he doesn't give off any information about himself and just tries to do his job, leading others to think that he doesn't want to open up because he knows they're all destined to die at one point.
Fanon: Fans near unanimously agreed to the idea of the Saniwa of this continuity being male, due to their masculine hairstyle and dress and Junko Minagawa (most known for voicing boys) being their Japanese voice actress. It also keeps consistent with other adaptations of the franchise, with the musical and stage plays also having male Saniwa.
Fan-Preferred Couple: Quite a few people like coupling the Saniwa together with Yagen, due to the pair being around the same height and the fact that Yagen seems to worry about them.
Harsher in Hindsight: Izuminokami's Kiwame training is this, given that both his letters and Katsugeki have him be present for his master's death in Hakodate.
Because of Tonbokiri getting gravely wounded in episode 5, fans have already added him among the ranks of the otherufotable polearm users with abysmal luck.
Episode 9 has Mutsunokami meet Sakamoto Ryouma in the flesh as part of his character arc, not unlike Yamatonokami meeting Okita Souji in Hanamaru. What's more, both historical figures are voiced by Daisuke Ono, and this isn't even the first time Ono has played Ryouma.
We get a cameo of Okita Souji during Episode 10, showing a more accurate depiction of him as he looks more in line with his real-life historical counterpart, (including the topknot hairstyle, making him look less attractive than how he normally looks in fiction). Given that Yamatonokami heavily based his appearance off of his master, and that in Hanamaru he and his old master look almost exactly alike, one can joke if Yamatonokami ended up looking the same as Okita here as well.
After all the struggle Unit 2 had with an enemy oodachi, Unit 1's handling of the brute near the end of episode 7 makes them look like a joke. Particularly, the scene where Mikazuki fought and eliminated the enormous oodachi on his own comes to mind.
The final battle in the last episode, Katsugeki, may count as well.
The fandom's love of the other Konnosukes and wish to see multiple Konnosukes in the game gets validated when 2020 introduces Kuronosuke, a more serious black Konnosuke from headquarters.
Ho Yay: Some of the next episode previews between the Touken Danshi tend to give off this vibe.
In the actual episodes themselves the real stand out moment is episode 8 when Izuminokami is Putting the Band Back Together. Mutsunokami outright throws a fit that Izuminokami hasn't asked him if he's going to keep fighting with Unit 2 yet, so Izuminokami quickly and calmly responds in the affirmative due to saving him in the Edo incident. Then Tonbokiri decides to tease them, saying that Izuminokami is the sort of person who saves his favorite food for last. Izuminokami promptly retracts his previous statement, saying he doesn't need Mutsunokami after all and he and Mutsunokami start fighting again. This gets referenced again in the next episode preview.
Mutsunokami's admiration of Ryouma at times feels like a little more than just admiration. When he finally gets a chance to speak with him, he briefly muses and considers running away with Ryoma without looking back. Even after the mission is successfully completed, his feelings for his former master only intensify:
"Even if you can't grip [your sword, the Mutsu-no-kami] or use it, keep it at your side until the last moment and let me see it. Because I love your way of life."
Horikawa and Izuminokami sometimes give off this vibe, as per the usual with these two. Horikawa's decision to try and save Hijikata from death isn't actually based on empathy for Hijikata himself, for example; rather, he decides to push forward for Izuminokami's sake, because Horikawa saw him overwhelmed with emotion after seeing his master again.
Like You Would Really Do It: At the same time, fans were skeptical of any sword truly dying in the anime. When Episode 6 came around and everyone survives despite the harsh battle, their skepticism was proven correct.
Lost in Medias Res: The most common complaint about the show from people unfamiliar with the games is that it doesn't do a good job of explaining who the characters are, why they're fighting, or what they're like. See Continuity Lockout.
"Touken Ranbu is my favorite Fate anime".note Aside from the studio connections, some ufotable fans are calling it a stealth Fate series based on the title naming scheme ("Katsugeki/[X]" compared to "Fate/[X]") and its focus on some form of historical figures, and started matching up certain plot beats and characters to keep up the joke.
With the show receiving a movie during the production of the Heaven's Feel film trilogy, some fans joked that ufotable was using the sword-heavy Touken Ranbu to get some practice in for Shirou's body breaking up into swords during a possible adaptation of the original route's Bad Ending.
Lazy Kebiishi/Kebiishi not doing their jobs.note Despite being known to show up during great time anomalies in the original game, the Kebiishi haven't shown up once to fight the Touken Danshi or the Retrograde Army with all the deviations that have been caused throughout the season. Some fans jokingly pit this against their behavior in Touken Ranbu - Hanamaru, where they showed up immediately to stop Yamatonokami from interfering with Okita Souji's next to last battle.
Narm: The phrase "protect(ing) history" has become this in the eyes of some fans. It's the central theme of the show, but they say it so much and elaborate so little on it that the phrase became hollow and silly over time. People had even joked about making a drinking game for how many times they say it.
In the first episode, a child trapped inside of her own home, which is burning around her, with no way out and her parents unable to save her. If Izuminokami hadn't saved the child, she would have perished in the fire.
In the second episode, Mutsunokami was deeply horrified on how many people were brutally massacred by the Revisionists. The scene was so bloody and a horrible sight to see.
In the fourth episode, Yagen is outnumbered by the enemies, with his life on the line, with his leg badly injured and severely outnumbered. This is one of the situations where he fears to face an unavoidable death. If Tsurumaru hadn't appeared and saved Yagen, his life would have come to an end.
In the fifth episode, after the Revisionists army succeeds in destroying Edo by setting the entire city on fire. This makes it feels like for once, the villains won instead of the heroes.
In the seventh episode, the abnormal "Street Slasher" Retrograde naginata has a deathly presence. He slaughters the entire shogun army and leaves a trail of bloody corpses he killed along the way. What's worse, none of the First Unit, the Unit 1 Konnosuke or the Saniwa has never seen that type before, as he can summon a horde of Retrograde soldiers and fuse several of them into a bigger and stronger version of an Ootachi.
In the tenth episode, after Horikawa realizes that history is already starting to slightly change and alter because of instability of the Bakumatsu time-space, he thinks it would be of little consequence to kill Ryoma, since this will prevent the eventual death and suffering of his former master Hijikata. Towards the end of the episode, it is implied that Horikawa is planning to push through with his plan to kill Ryoma and thus change history, if it means saving his former master from his demise.
In the eleventh episode, after the destruction of the Satsuma residence, many people lost their lives to the tragic events caused by the Retrograde Army. Horikawa only manages to save a young girl, who was the only one to survive the fire.
In the twelfth episode, the Saniwa's body begins to disappear due to reaching their limit for staying in the past for too long. Had they not made it back in time, it's implied that they would cease to exist.
After the Saniwa reveals the final Revisionist army numbers, it's inevitable that both units would have to overcome this unavoidable situation during the final battle. There might even be a chance that none of them will make it out alive after this due to the sheer grand scale of the fight.
Shipping: Some ships were born from the diverse cast of characters in the two main units, shipping together characters that aren't usually paired/associated with each other in canon or in the fandom mainly due to their interactions in the show, being on the same unit or even simply being primary characters in Katsugeki at all. Some examples include:
Yagen / Tsurumaru
Horikawa / Mutsunokami
Mikazuki / Izuminokami
Yamanbagiri / Honebami due to the episode 7 next episode preview
Unit 1 Konnosuke/Unit 2 Konnosuke
Shocking Moments: Tonbokiri's fight in episode 5, and his critical injuries against the Ootachi were seen as this. Most people didn't think he'd be the first to get hurt like this, considering his position in the story and his middling popularity compared to some of the other swords, but when his cracking happened, Twitterblew up.
Tough Act to Follow: With the overwhelmingly positive reception and success of its brother anime Touken Ranbu - Hanamaru, this series being its emotional opposite had big shoes to fill. While it did do well for itself, it wasn't nearly as universally liked.
They Wasted a Perfectly Good Plot: Early in the show, Izuminokami threatens to kill the little girl they save from a burning building if he finds that she could drastically change the timeline with her survival. The idea of even regular, minor people affecting history on par with a named historical figure or event is interesting, but aside from episode 5 we don't get to see a lot of this in the plot, and the latter half of the show is entirely about preserving a well known historical event. Even still, there are some fans who wanted to see the little girl return in a later episode.
Viewer Gender Confusion: Quite a few people who were unfamiliar with Katsugeki's source material believed Yagen Toushirou was female until he spoke.
Unexpected Character: Many fans found the Saniwa in this series to be this. While Saniwas are usually relegated to background roles and offscreen assignments, they're never the main character material in official or officially endorsed works. (Fan portrayals of one, however, are a different story.)
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