Moka Kamishiraishi as Sakuta Minami

Kanata Hosoda as Moji Shouhei

Yuki Saito as Minami's Mother

Etsushi Toyokawa as Minami's Biological Father

Yudai Chiba as Moji's Older Brother

Kanji Furutachi as Minami's Stepfather

Tōru Shinagawa as Moji's Grandfather

Hina Yukawa as Miyaji

Miyu Tomita as Koteko (voice)

Daisuke Namikawa as Count Cement (voice)

Takahiro Sakurai as Mortar (voice)

Tatsuhisa Suzuki as Concretarō (voice)

Show Hayami as Prince Shōtoku (voice)