Ken Inami is a 17-year-old student at Hamasaki High School, possessing black hair and grey eyes. His name signifies "healthy, strong" (健) with a surname meaning "that one" (伊) and "wave, breaker" (波). Passionate about soccer, he plays regularly and aspires to attend film school. He works part-time at the family restaurant Ressac alongside classmate Megumi Souma. His closest friend is Shouta Nakamori, captain of the school soccer club.

He dates fellow student and pianist Hotaru Shirakawa, though their relationship faces strain during one summer. At this point, his path branches: he might reconcile with Hotaru or explore connections with others like childhood friend Tomoe Tobise, swim team member Takano Suzuna, co-worker Megumi Souma, Hotaru's older sister Shizuru Shirakawa, or his teacher Tsubame Minami. Each choice leads to distinct outcomes, ranging from reconciliations to breakups.

In subsequent appearances, Ken and Hotaru are consistently shown together as a couple. They feature in the *Memories Off 3.5* OVAs, supporting characters like Inori Misasagi through romantic challenges. He also appears in *Memories Off ~Sorekara~* with Hotaru, where Shizuru works as a restaurant deputy manager. Ken often provides advice and perspective to others navigating relationship issues.

His personal development differs across storylines, but consistently revolves around balancing his own ambitions with his romantic commitments.