Gakusha serves as a sailor mouse under Captain Yoisho, his childhood friend. Known for his knowledge and cleverness, he is distinguished by his large glasses and notably short tail. As part of Yoisho's crew, he aids Gamba and his companions on their voyage to defend an island mouse colony against the weasel clan led by Noroi. Gakusha consistently provides intellectual support, applying his intelligence to strategic efforts against the antagonists. He is depicted as dependable and calm, traits that complement Yoisho's leadership and Gamba's adventurous spirit. His background prior to joining the sailor crew remains unexplored, and his role consistently focuses on supporting the primary mission against Noroi's forces without significant individual story arcs beyond this collective objective.