Ren Miyagi is a third-year student and competitive badminton player at Yokohama Minato High School, active in both singles and doubles tournaments. He frequently partners or competes alongside teammates Ryo Mizushima, Kento Yusa, and the Higashiyama twins during these events.

His documented match history includes notable performances. At the Takamatsunomiya Cup squad event, Miyagi reached the singles final but fell to teammate Ryo Mizushima in two closely contested sets, both ending 21-19. Earlier in the same tournament's singles event, he advanced to the semifinal where Kento Yusa defeated him in straight sets. Miyagi also engaged in inter-school competition, such as a practice doubles match where he paired with an unnamed player from Saitama Futaba; they lost one set decisively 8-21 to the duo of Ryo Mizushima and Shohei Sakaki.

Ren Miyagi's background story, personal development, and character arc across all official media remain undocumented in the available information.