Ao no Hako

Blue Box follows Taiki Inomata, a dedicated high school badminton player whose early mornings at the gym are brightened by the presence of Chinatsu Kano, a celebrated member of the girls’ basketball team. What begins as a quiet crush grows into something more complicated as their daily routines start to overlap, pushing Taiki to take his training—and his feelings—more seriously than ever.

Set among school clubs, tournaments, and the pressure to improve, the series mixes gentle romance with the steady rhythm of sports life. With friends and rivals around them—and emotions that don’t always stay neatly out of the way—Taiki and Chinatsu navigate ambition, awkward closeness, and the uncertainty of what comes next.