In junior high, Ryu and Zen were basketball teammates. Now in high school, they’ve taken different paths—Zen plays on the school team, while Ryu earns money playing underground betting basketball run by gangs. One day, Zen’s basketball team faces disbandment when senior members are caught using drugs.

While delivering coffee, Zen visits a street basketball court and ends up substituting for an injured player on Ryu’s team. Meanwhile, the school team restarts under a new coach, Ton, but lacks enough players. Coach Ton sets his sights on strengthening the team by recruiting someone new.

Ryu joins the school team and is reunited with Zen, but the other members treat him like a delinquent. Meanwhile, the gang that controls the street basketball scene grows impatient as Ryu stops showing up, and they resort to drastic measures.

When Zen is kidnapped by Kyu, Ryu rushes to help but finds Atom has already rescued him. Feeling uneasy, Ryu begins escorting Zen to and from school. When they arrive at Zen’s home one day, Atom is already there—sparking silent but intense tension between the two rivals.

With an important match approaching, the team goes on a training retreat. Tensions flare between Ryu and Zen, prompting the coach to tie their wrists together and force them to spend 24 hours as a pair. During this time, Atom visits, adding fuel to Ryu’s jealousy.

Zen’s grandmother suddenly collapses and is hospitalized. Faced with costly surgery, Zen is at a loss. Atom proposes entering a 3-on-3 basketball tournament to win the prize money. He, Zen, and Ryu form a team and strive to win together.

As the basketball team gains popularity, Coach Ton’s troubled past is uncovered. The school board begins investigating his dismissal. Ryu pleads with his mother to help, and she agrees—but only if he meets a difficult condition.

After intense training, the team wins their first game, thanks in large part to Ryu. Their next opponent is Atom’s powerhouse school. Zen feels awkward but agrees to a fair match. Meanwhile, Ryu struggles to leave the world of underground basketball behind.

The team progresses to the upper rounds of the tournament, but their funding is cut, threatening their participation. Ryu refuses to speak with his mother, the alumni association president. To raise funds, the team decides to run a dunk tank at the school festival. Meanwhile, the coach, previously sober, starts drinking again.

The semifinals begin without Ryu. Struggling without him, the team fights back in the second half and wins. Despite their success, the school board insists on shutting the team down. Not wanting to burden his grandmother any further, Zen decides to join a team in Phuket that offers a scholarship after the finals.

Ryu is injured by Inter-High players and recovers at Zen’s home. Atom proves his innocence by confronting his teammates. Learning that Ryu is staying over, Atom finds a reason to stay at Zen’s house too, intensifying the silent rivalry between him and Ryu.

After confessing his feelings to Zen, Ryu and Zen’s relationship takes a turn. But Ryu is abducted by the gang trying to lure him back. Zen, worried after losing contact with Ryu, tracks his location and charges into the gang’s hideout alone to save him.