Riiri is a mouse beastfallen with white fur and a squeaky voice. Despite being over twenty years old, she retains a child-like physical appearance. She exhibits a notably timid and shy personality, often lowering her gaze and avoiding crowded environments due to discomfort in social settings. Riiri assists with duties at the church as a commendable assistant to the Blind Priest, whom she trusts deeply. This trust establishes her as a reliable support figure within the church's operations. She demonstrates proficiency in cooking, a practical skill that contributes to her community role. Her reserved nature and focused work ethic define her interactions and presence throughout the narrative.