Bobo is the best friend and childhood companion of the protagonist, Gamba. Originally a town mouse, he shares the same starting environment as Gamba before their adventure begins. Bobo is easily recognized by his distinctive green fur, which sets him apart visually from other characters. His personality is defined by gluttony and an easygoing, absentminded nature, traits that are reflected in the origin of his name. One of his most practical abilities is his sensitive nose, which he frequently uses to locate food during their travels.

Bobo’s initial motivation for leaving town is a combination of hunger and the threats present in their home environment. He joins Gamba on the first leg of their voyage, with the simple goal of accompanying his friend to see the sea. At a harbor, the pair encounter an injured mouse named Chuuta, who desperately appeals for help to defend the island of Yumemishima from the cruel white weasel Noroi and his clan. While Bobo is initially filled with fear and reluctant to risk his life for strangers, he ultimately overcomes his hesitation and commits to aiding the defense effort alongside Gamba. His role in the story involves supporting Gamba’s decision, helping to recruit experienced sailor mice at the harbor, and sailing with the group to confront the Noroi Clan. As Gamba’s closest friend, Bobo provides loyal support throughout the dangerous mission, even though his gluttonous and easygoing nature contrasts with Gamba’s more energetic and justice-driven personality. In later adaptations, particularly the 2015 3D CG film Gamba: Gamba to Nakama-tachi, Bobo’s narrative role is significantly reduced to a secondary character. In that version, his original functions as Gamba’s primary companion and fellow town mouse are largely transferred to a new character named Manpuku.