After accidentally breaking a statue of a kappa that serves as the guardian god of the district of Asakusa, middle school students Kazuki, Toi, and Enta are transformed into kappas by Keppi, the prince of the Kappa Kingdom. They come to assist Keppi in collecting the Dishes of Hope, which fulfill the wishes of whoever possesses them. Dishes are acquired by collecting the shirikodama of zombies created by Reo and Mabu, agents of the Otter Empire. The Otter Empire, in the guise of “Kappazon, Inc.”, controls society by manipulating the desires of the masses, and has been the enemy of the Kappa Kingdom for generations. To defeat the zombies, the boys must make the sound “Sarazanmai”, which can only be produced when the three are united. They struggle to connect, as each time the sound is made, one of the boys’ secrets is revealed.