A small, lone Kappa miraculously survives over 200 years into modern day Japan, when he is found by young Koichi. Coo, who is secretly adopted by Koichi's family, searches with his new human friend for unpopulated places in hopes of finding any remaining of his kind.
冨澤風斗
as Coo (voice)
Takahiro Yokokawa
as Kouichi Uehara (voice)
田中直樹
as Yasuo Uehara (voice)
松元環季
as Hitomi Uehara (voice)
なぎら健壱
as Coo's Father (voice)
Nanako Hirata
as Koichi's Classmate (voice)
池田恭祐
as Koichi's Classmate (voice)
Kazuki Matsuoka
as Koichi's Classmate (voice)
Souta Murakami
as Koichi's Classmate (voice)
Saki Yoshihara
as Koichi's Classmate (voice)
Kereo Yoshita
as Koichi's Classmate (voice)
西田尚美
as Yukaki Uehara (voice)
