- All-Star Cast: In the Japanese version, popular seiyuu Junichi Suwabe, Ayumu Murase, Kouki Uchiyama, Shun Horie, Mamoru Miyano and Yoshimasa Hosoya are playing characters in this Anime.
- Anime First: While a manga series and a light novel were released before the anime aired, the manga is more of a spin-off that doesnt necessarily cover anything related to the Animes plot.
- I Knew It!: Quite a few fans had guessed that Kazuki would have a crossdressing subplot from as early as the Connections trailers, where they had seen his pink keychained phone and slightly pink fingernails and guessed he had been doing it from that.
- Before the Anime aired, The fandom had guessed due to Mabus inhumanly pale appearance compared to the main cast, that he had died before the events of the shows main plot and is a zombie. In episode 6 and 7, it is revealed that this is the case and that he was fitted with a mechanical heart to keep him alive.
- A Zombie battle involving Mabu as the subject of desire was guessed nearly from the beginning.
- Due to the color scheme of the boys being prominent and resembling the colors of the pansexual pride flag, it was assumed that Sarazanmai would tackle themes of pansexuality primarily, particularly theorized in the western fanbase and would tie into the largely western theory that Kazuki was transgirl once the show began to air. Ultimately, this theory was jossed as themes of pansexuality were never touched upon in the show.
- In the early series, some fans had theorized that Kazuki was using crossdressing for Haruka as an excuse for a secret love of the act, or surface area problems that have his biggest secret be that he's a trans girlnote . The crossdressing was entirely tied to Haruka; after episode 6, he doesn't crossdress again since he resolved his family issues.
- Quite a few people had guessed that Reo would go berserk and turn into a Kappa Zombie due to his increasingly unhinged feelings for Mabu. The reverse is true; Mabu is zombified due to his desire to be with Reo, and Reo has to take him down, though this was hinted at in the opening.
- A running theory in the Japanese fandom was that Reo and Mabu were also an Interspecies Romance between an Otter and a Kappa. Both are Kappa.
- Up until the end, there were camps and theories for which two boys would end up becoming an official couple based on the Ship Tease between them. Kazuki/Enta, Toi/Kazuki, or Toi/Enta. Ultimately, In the end none of the boys ended up romantically paired with each other instead remaining the friend trio making Reo/Mabu and Sara/Keppi, who get married in the finale, the only canonized romantic pairs in the show.
- In the early series, some thought that Sara's backstory had to do with her Insert Song "Afterschool Kappa" (in which the singer is a ghost who wanders around her school and hometown after committing suicide). It couldn't be further from the truth, given she's really the kappa princess.
- Man of a Thousand Voices: In the Japanese version, all the zombies are voiced by the same man, Ryo Kato.
- Meaningful Release Date: Episode 9, focused on Chikai and Tooi, originally aired on Brother's Day in Japan (June 6).
- Non-Singing Voice: Averted with both of the insert songs for the English dub.
- Relationship Voice Actor:
- What Could Have Been:
- For episode 2, Tooi was going to be momentarily possessed by the Cat Zombie and try to decapitate Enta with a huge pair of scissors.
- Official storyboard art shows that Reo and Mabu were initially going to dance up an escalator for their "Kawausoiya" part. The artbook further elaborates that the scene was supposed to be more musical inspired, with the dance instead being a musical number and the theme being more The Phantom of the Opera inspired. The musical theme is given a nod in Episode 9, where Reo dances and sings home with moves straight out of West Side Story.
- Enta's sister Otone and the boys' homeroom teacher were not originally the same person. There was also a point in time where Otone would have been friends and classmates with Sara.
- Keppi would have had coloring more similar to a typical kappa in his concept arts, and the wifi symbol would have been on his head from the start; the design itself remained largely the same. In the art book, his early name would have been written as "KP".
- The transformation sequence would have had the boys' human bodies being blown off and burned away, to make their kappa forms' "dead yet alive" motif more apparent.
- Chikai would have been a little younger in the earlier drafts, with a look that's more delinquent like than gangster like.
- Spoiled by the Merchandise: The first light novel covers the events of the first six episodes, plus reveals the identities of Reo and Mabu. This book was released days apart from the show.
Trivia / Sarazanmai