Shinbei is relaxed, happy-go-lucky, and kind. He is a gourmand, and often hungry; he can easily be persuaded to act with the promise of food, similarly to how Kirimaru is driven by wealth. Shinbei is a lot slower than his friends in class and is supported often by Rantarou and Kirimaru, but he has occasional moments of brilliance where he says something smart or shows great physical strength. The shortest of all the known nintama, Shinbei is stout and chubby; sometimes he is shown having an average physique when he is unwell. He has tidy, flowing hair tied into a short ponytail - his bangs are shown to be parted down the middle when he is not wearing his hood. He has super-thick eyebrows, dot-like eyes, and a wide mouth. When Shinbei runs out of hair conditioner, his hair turns incredibly hard and bristly, and stands on end (this also applies to his eyebrows on one occasion). His casual wear consists of a periwinkle kimono with white polka dots and a wide red hakama that goes all the way down to his ankles (due to his short stature).
