Gamba no Bouken

Gamba, a brown mouse, embarks on a sailing journey with his childhood friend. They gather experienced mice sailors at a harbour. They encounter Chūta, a mouse who has been injured and is seeking help. He appeals for Gamba and Bōbo to assist him in defending the island of Yumemishima and its inhabitants from the cruel and wicked invading Noroi Clan. Gamba elects to sail to Yumemishima with Chūta to help defend the island, and Gamba recruits more mice to join their cause on the island.