Bobo is the best friend and constant companion of the title character Gamba, sharing his background as a town mouse who grows tired of the hardships of their everyday life. He is visually distinct, possessing fur of a notable green color that sets him apart from other characters. His personality is primarily defined by a love of food and an easygoing, somewhat absentminded nature, and his name is a direct reflection of this carefree disposition. Despite his gluttonous and laid-back tendencies, he possesses a sensitive nose that proves to be a practical skill, particularly useful for locating food during their travels.

Bobo’s initial motivation for leaving his home is a combination of persistent hunger and the ever-present threat of predators, which drives him to join Gamba on a journey to see the sea. This voyage forms the core of his role in the story, as he is present when the pair first encounter an injured mouse named Chuta at a harbor. Chuta desperately appeals for help to defend his home island of Yumemishima from the tyrannical weasel Noroi and his clan. While Gamba is immediately and recklessly eager to help, Bobo initially reacts with fear and reluctance, being unwilling to risk his life for strangers. However, he ultimately overcomes this hesitation and commits to aiding the cause, joining Gamba and a group of other sailor mice on the dangerous mission to confront Noroi. His primary relationship is with Gamba, whom he supports as a loyal friend, and his development is marked by this progression from a creature concerned with simple survival to one willing to face grave danger for the sake of others.

Within the broader franchise, Bobo’s role has been subject to change. In the 2015 computer-animated film adaptation Gamba: Gamba to Nakama-tachi, his narrative importance is significantly reduced to a secondary character. In this version, his original functions as Gamba’s main companion and fellow town mouse are largely transferred to a new character named Manpuku.