After accidentally breaking a statue of the guardian god of the Asakusa district, middle school students Kazuki, Toi and Enta are transformed into kappas -creatures from japanese folklore- by Keppi, self-proclaimed prince of the Kappa Kingdom. If they want to regain their human form, they must collect the five Dishes of Hope for him, which fulfill the wishes of whoever possesses them. To do so, they will fight against the kappa-zombies and extract their "shirikodama", the mythical organ containing humans' deepest desires. Two policemen, Reo and Mabu, are the ones behind this evil scheme, turning humans into zombies as agents of the Otter Empire, enemy of the Kappa Kingdom since ancient times. In the guise of "Kappazon, Inc.", they control society by manipulating the desires of the masses for their own goals. To succeed in their mission, the boys must be connected through the "Sarazanmai", revealing their most intimate secrets in the process...
After accidentally breaking a statue of a kappa at a shrine in Asakusa, middle school student Kazuki Yasaka encounters Keppi, heir to the throne of the Kappa Kingdom. He, along wi…
Keppi gives the group a Dish of Hope as thanks for helping him, which grants one wish to whomever possesses it, and informs them that they can earn more plates by defeating more z…
Enta, who has a crush on Kazuki, wishes to earn a dish so that Kazuki will return to playing soccer with him. Reo and Mabu extract the desires of Otone's boyfriend (who, unbeknown…
Kazuki asks for Toi's help to kidnap Sara and so that he can take her place during a meet-and-greet that Haruka plans to attend. Toi's backstory is revealed through a flashback – …
Toi attempts to kidnap Sara, though she evades him by transforming into a kappa, exposing Kazuki's crossdressing to his family. Kazuki reveals that he is adopted, and that he blam…
The group rescue Haruka after he is kidnapped by Reo, and are transformed back into human form. Keppi explains that Reo and Mabu are agents of the Otter Empire, who have been at w…
In a flashback, Mabu is brought back to life with a mechanical heart transplanted by Otter, though Reo believes that Mabu is merely a re-animated facsimile. Chikai's criminal deal…
Chikai and Toi make preparations to leave the city. Enta returns the Dishes of Hope to Kazuki, but they are confronted by Reo and Mabu, who intend to use the dishes to restore Mab…
Keppi transforms a hospitalized Enta into a kappa so that he and Kazuki can recover the dishes. Reo witnesses Otter performing sexually-charged "maintenance" on Mabu's heart; when…
Kazuki, Enta, and Keppi encounter Dark Keppi, the corporeal form of half of Keppi's shirikodama held by the Otter Empire. Otter, having learned of Reo's plan to use the dishes on …
Toi begins to destroy his connection to Kazuki and Enta, but ultimately chooses to preserve it. Keppi fuses with Dark Keppi, with assistance from the group and a revived Reo and M…