Natsuki Ise is a second-year student at Kanagawa High School and serves as a center on the school's rugby club. He began playing rugby in high school after being invited to join by a teammate named Hachiouji, and he has expressed a desire to eventually switch to a forward position. Prior to joining the rugby club, Ise had been involved in delinquent activities, but he is portrayed as rather shy and deeply embarrassed by his older brother Haruki's rude behavior and open disrespect toward rugby players. His motivation for dedicating himself to the sport stems from rugby offering him an escape from his worries and from the tension with his brother. Ise works hard during practices, viewing the game as a way to distance himself from his past and his family difficulties. As a center, his role on the field involves linking the forwards and backs, though the series shows him as a capable and determined player who measures 1.74 meters tall and weighs around 72 kilograms. His key relationships within the story include his bond with Hachiouji, who first brought him into the club, and the strained dynamic with his older brother Haruki, whose attitude he finds humiliating. Over the course of the series, Ise develops through his commitment to the team, using rugby as a constructive outlet for his energy and gradually growing more comfortable within the club environment.