Shiro is a young kashiwa-motchi Dochamon, a guardian spirit in training destined to protect one of Japan's 47 prefectures. His name, meaning "white," mirrors his pale coloration. Within Dochamon society, Shiro aspires to become a respected and fully developed guardian but faces obstacles due to perceived immaturity and frequent cowardice. These traits cause other residents to doubt his potential and lead him to make mistakes. His core motivation stems from a desire to overcome these shortcomings and achieve respectable status among his peers.

Okutowing serves as Shiro's primary rival, gaining greater favor from fellow Dochamons and confidently declaring his imminent graduation from their trainee world. This creates a benchmark against which Shiro measures his own slower progress, fueling his efforts toward maturity.

During the concluding episodes of the first season, Shiro experiences a pivotal expansion of his world: he travels to the real world and interacts directly with humans. After this journey, he returns to the Dochamon realm. His reappearance marks the beginning of the second season, as indicated by its first episode's title, confirming his continued participation in subsequent adventures.