Shijin is a wandering doctor mouse known for reciting poetry aloud when intoxicated, a habit reflected in his name, meaning "Poet." He possesses exceptionally sensitive hearing, capable of detecting sounds others cannot, which aids the group during missions. Recruited by Gamba as one of fifteen companions opposing the weasel Noroi, Shijin contributes his medical expertise. His poetic nature and acute hearing form distinct aspects of his role, highlighting the diverse skills within the group.