TV-Series
Description
Kazuki Yasaka is a 14-year-old middle school student and one of three protagonists transformed into a kappa after accidentally breaking a golden kappa statue in Asakusa. He possesses reddish-brown eyes and burgundy spiky hair, usually dressed in his school uniform: a white shirt with light blue markings, a red tie, blue trousers, and black shoes. He also wears a casual outfit featuring a pink-striped shirt printed with a cartoon kappa and the text "Ka-e-ru".

Adopted by his aunt and uncle following his biological mother's inability to raise him due to mental health struggles after his biological father's death, Kazuki lives with his younger brother, Haruka Yasaka. Haruka uses a wheelchair after an accident Kazuki blames himself for, believing Haruka got hurt trying to connect with him. This deep guilt fuels Kazuki's primary motivation: he meticulously crossdresses as idol Sara Azuma, mimicking her speech and mannerisms to send daily selfies to Haruka, maintaining the illusion of a personal bond between Haruka and the idol. He strictly adheres to three rules: always carrying a cardboard box, checking Sara's show for daily selfie themes, and sending the photos exclusively to Haruka.

His relationships are complex. He and childhood friend Enta Jinnai were soccer's "golden duo," but Kazuki quit the team abruptly before the series, straining their bond. Kazuki remains unaware of Enta's romantic feelings, even dismissing a leaked memory of Enta kissing him as a prank. Kazuki encounters delinquent Toi Kuji during Toi's attempted car theft, inadvertently photographing Toi while crossdressed as Sara. After both break the kappa statue, they transform alongside Enta. Later, Kazuki collaborates with Toi to kidnap Sara Azuma for a fan event and seeks magical "Dishes of Hope" to aid Toi's brother, hoping Toi won't leave.

As a kappa, Kazuki retains his spiky hairstyle but gains green skin, a head plate, a shell with a swirly pattern, and a large red neckerchief. To regain human form, he must join Enta and Toi in performing "Sarazanmai"—a unified cry extracting "shirikodama" from zombies, which leaks one of their secrets each time. Kazuki's first leaked secret reveals his crossdressing, prompting his defiant declaration: "I never asked anyone to understand me". His character evolves from isolation to interdependence: he risks his existence to save Haruka and later collects all five Dishes of Hope to revive Enta from critical condition. After Toi serves time in juvenile detention, Kazuki welcomes him home, and the trio plays soccer while performing a symbolic Sarazanmai.