Chikuma Tanesato is the younger brother of the cheerful, extroverted college student Madoka Tanesato and cousin to Mizuto Irido. An elementary school student himself, he possesses medium-length dark brown hair and brown eyes. Chikuma is characterized as extremely shy, fitting the shrinking violet trope; he rarely speaks, earning him the descriptor of the quiet one. This personality creates a distinct sibling yin-yang dynamic with his older sister. The significant age gap between them places them in practically different generations. Chikuma harbors a precocious crush on the high school-aged Yume Irido. His narrative role centers on family interactions, particularly during visits involving Mizuto and Yume.