Nagayoshi Onagawa is a third-year student at Sōshūkan High School, also known as Ao High School, and a member of the boys’ rhythmic gymnastics team. He originally hails from Miyagi Prefecture and his family runs a fish shop. Onagawa is widely recognized as the club’s mood-maker, bringing energy and laughter to his teammates with his bright and fun-loving personality. He enjoys joking around, especially by giving everyone odd nicknames, and has a fondness for cute girls and female idols. Despite his cheerful exterior, Onagawa sometimes experiences moments of uncertainty or feeling lost, but the support of his friends helps him recover and stay positive. He is a childhood friend of Masamune Shichigahama and Keisuke Tsukidate, and the three share a close bond that predates their time on the team. Onagawa is a founding member of the Ao High rhythmic gymnastics club and considers himself its ace, a claim that the other members do not dispute. He is noted for being the most flexible member of the team and particularly skilled at tumbling. Over the course of the story, Onagawa’s role is that of a supportive and experienced senior who helps guide the younger gymnasts, including the new first-year members like Shotaro Futaba. His development involves learning to rely on his teammates during difficult moments and channeling his lighthearted energy into serious competition. Onagawa also enjoys giving people funny nicknames and is quick to lift the team’s spirits during training and events. He has medium-length blonde hair and brown eyes.