Ren Kiryū belongs to the Amanogawa Futsal Club and is enrolled in the Star Course at Amanogawa Academy. He works as a sought-after young model, having participated in overseas fashion collections. His modeling career began after being scouted, which he accepted primarily motivated by financial necessity. The clothes he wears are provided by his modeling agency.

On the futsal court, he embodies a lone wolf persona, dismissing team unity and coordination. He prioritizes individual skill, convinced that personal ball-kicking prowess guarantees success. This mindset leads him to skip regular team practices, favoring intense 1v1 matches instead. Despite his solitary approach, he stands undisputed as his team's strongest and most talented player.

His background involves family challenges: a mother frequently occupied with work and an older brother with whom he once practiced shooting. Financial strain from his family situation heavily influenced his decision to pursue modeling.

Daily, he routinely neglects personal care and proper meals due to his singular obsession with futsal, a habit that consistently worries his teammate Shun Shirakawa, who takes it upon himself to look after Ren. His hobbies include muscle training, and he possesses broad athletic skills. He enjoys animals and pouch jelly but dislikes noisy environments and people. Fish ranks as his least favorite food. His musical preference leans towards jazz, particularly solo performances over band arrangements.

Additional details confirm he is a third-year student with a Scorpio star sign. He remains the only player in the franchise's media representation who lacks a designated profile photo.