Three middle schoolers – Kazuki Yasaka and his classmates Toi and Enta, inadvertently break a Kappa statue and are transformed into Kappa by Keppi, the prince of the Kappa Kingdom. To return to their human forms, they must collect dishes of hope or shirikodama from Kapa-zombies by making a sound – “Sarazanmai”. However each time they do, their secrets and inner conflicts are revealed.