Reiko Yoshinaga, a 19-year-old Siren Academy student, balances kendo practice with a sharply edged demeanor. Her waist-length crimson hair, often swept into a high ponytail, frames piercing brown eyes that mirror her occasionally combative nature. Though prone to bullying tendencies, she navigates an unlikely friendship with Haruka Tachibana—an 18-year-old peer balancing dual roles as student and occasional instructor. Their dynamic persists amid Reiko’s confrontational streaks, anchoring her social presence within the academy’s routines.