Two different high school children - a swimmer and an academic - set off on a quest together one summer.
Moka Kamishiraishi
Sakuta Minami
Kanata Hosoda
Moji Shouhei
Yuki Saito
Minami's Mother
Etsushi Toyokawa
Minami's Biological Father
Yudai Chiba
Moji's Older Brother
Kanji Furutachi
Minami's Stepfather
Tōru Shinagawa
Moji's Grandfather
Hina Yukawa
Miyaji
Miyu Tomita
Koteko (voice)
Daisuke Namikawa
Count Cement (voice)
Takahiro Sakurai
Mortar (voice)
Tatsuhisa Suzuki
Concretarō (voice)
Show Hayami
Prince Shōtoku (voice)
