Sally Hawkins

as Mum (voice)

Cillian Murphy

as Dad (voice)

Raffey Cassidy

as Becky (voice)

Aaron MacGregor

as Michael (voice)

Ken Watanabe

as Kensuke (voice)

Alfred Kodai Berglund

as Michiya (Kensuke's Son) (voice)

Ken Ochiai

as Nagasaki Announcer (voice)

Cavin Cornwall

as Additional Voices