Chizuru Tachibana is a high school student and dedicated puppeteer, regularly practicing her craft and performing in school puppet shows. She deeply admires Sakon Tachibana, viewing him as both a gifted puppeteer and detective. Their strong friendship sees Chizuru consistently supporting Sakon during his investigations.

Characterized by calmness and analytical thinking, Chizuru acts as a grounded counterpoint to Sakon's more eccentric nature. She demonstrates resourcefulness in investigations, adeptly analyzing suspects' motives and providing reasoned advice, serving as a stabilizing influence within the group.

Her development centers on her increasing involvement in Sakon's cases, evolving from an observer to an active participant who applies sharp observational skills and logical reasoning to help solve mysteries. Throughout, her dedication to puppetry remains a constant, reflecting both her artistic commitment and the bond she shares with Sakon through their craft. Her portrayal focuses on this supportive role within the main narrative.