Josephina the Whale

Naomi Jinbo

as Santiago 'Santi' Costa (voice)

Kazue Takahashi

as Josephina (voice)

Takashi Tanaka

as Rafael Costa - Santi's father (voice)

Toshiko Sawada

as María de Costa - Santi's Mother (voice)

Tomiko Suzuki

as Rosa Costa - Santi's sister (voice)

Yoshiko Matsuo

as Celia - Santi's best friend (voice)

Chiyoko Kawashima

as Benita - Maid (voice)

Natsuko Kawaji

as Santi's Grandmother (voice)

Eken Mine

as Santi's Teacher (voice)

Yonehiko Kitagawa

as メルチュウル