* Based on children's books by Saitou Atsuo. Re-edited from a 1975 TV series.

When a badly injured mouse staggers off a ship in Tokyo Harbor, he tells the local mice that he has escaped from Devil's Island, where Noroi, the evil white weasel, has crushed the mice with his reign of terror. Tough-guy Gamba rashly promises to help depose Noroi.

Source: The Anime Encyclopedia

AniDB | MAL | TVDB

Full story: Gamba no Bouken