Ryuu

Ryuu is violent, confrontational and much less restrained than Mitsui's basketball acquaintances. During the gym incident, he is willing to escalate a school fight with weapons rather than limiting himself to fists.

He reacts badly to resistance and continues attacking even when the basketball players refuse to give Mitsui the confrontation he wants. Rukawa's defiance in particular draws his attention.

The anime-only continuation makes him more ambitious, depicting him as willing to challenge existing delinquent hierarchies once Mitsui withdraws from that world.

Ryuu is an experienced street fighter but has no formal athletic specialization established in the story. He relies on physical aggression and whatever objects are available during the gymnasium brawl.

Against Rukawa, he uses a broken mop to inflict a serious-looking head wound. Rukawa nevertheless remains capable of fighting and retaliates decisively.

Ryuu's abilities are therefore dangerous in an uncontrolled brawl but do not place him alongside exceptional fighters such as Yohei Mito or Sakuragi.

Ryuu participates in Mitsui's attempt to provoke Shohoku's basketball team into fighting. Because school violence could disqualify the club from competition, the attack threatens the team's season as much as the players themselves.

He becomes Rukawa's principal opponent during the brawl, striking him with a broken mop before Rukawa knocks him down.

Mitsui eventually abandons the delinquent group and returns to basketball after confronting his unresolved desire to play again.

The television anime gives Ryuu an additional storyline in which he gathers followers and comes into conflict with Tetsuo. This continuation is anime-original rather than part of Takehiko Inoue's manga.

Hisashi Mitsui is the basketball player whose delinquent circle Ryuu initially belongs to. Their paths separate when Mitsui returns to Shohoku's basketball team.

Kaede Rukawa fights Ryuu during the gymnasium attack and is injured by his improvised weapon before retaliating.

Tetsuo is another major member of Mitsui's delinquent circle. In the anime-original continuation, Ryuu comes into conflict with him.

Yohei Mito and the rest of Sakuragi's friends oppose Mitsui's gang during the gymnasium incident.