Hiromoto Utou is a second-year student at Saitama Kouyou High School who serves as both the director of the school's kabaddi department and the captain of its team, where he wears the number 1 jersey. Known by the nickname Hiro, he is renowned for his many techniques and skills on the kabaddi court and is recognized for his good personality. Hiromoto was previously a junior of Masato Ojo and Kei Iura during junior high school.

In appearance, he has dark hair and brown eyes, stands 169 centimeters tall, and weighs 65 kilograms. His blood type is AB and his birthday is October 12. He wears his school's yellow and orange kabaddi uniform.

The name Hiromoto combines the characters for "big" or "great" (大) and "beginning," "former time," or "origin" (元). His surname, Utou, means "right" or "right-hand side" (右) and "wisteria" (藤).