In a small town, a boy named Keiki makes a promise to the girl next door before she moves away: he will become a basketball champion so they can meet again at the national tournament. Driven by that vow, he throws himself into training but quickly loses confidence after being decisively defeated by a genuine basketball prodigy. He quits the sport entirely. Time passes, and as his emotional wounds begin to heal, an unexpected newcomer arrives and reignites his passion for the game. Keiki must learn to overcome his past failures and rediscover what drew him to basketball in the first place. The story is set in a contemporary Japanese school environment, centered on high school basketball competition. The narrative explores themes of resilience, friendship, and the pain of growing apart. The series follows Keiki's gradual return to the court and the new relationships that help him move forward.