At Salvia Academy, there was a gang leader group led by Daisuke Tonoyama and a female gang leader group led by Yukari Sakuraeda. There, Rock Umezato (his mother's maiden name. Later, he was introduced as Rock Brown in the work using his father's surname), a Japanese-American half-boy, transferred to the school. Rock's father was a wealthy man who was the president of a trading company, and had donated a large sum of money to Salvia Academy. The group cheered and slandered Rock as he got out of the car (under the assumption that he didn't understand Japanese). Rock initially waved his hand with a smile, but then responded in Japanese to the teachers who greeted them, and then glared at the bancho group with a surprised look on their face. Following the greeting in the classroom, Rock suddenly sanctioned Tonoyama with an iron fist, but he was defeated by Tonoyama, who has a rank in judo. After that, Rock, who got acquainted with Yukari Sakuraeda, declared that he would challenge him to a duel again as soon as he mastered judo. However, Yukari, who is an ally of Rock, was asked by her teacher to help her with the volleyball match on the day of the duel, so she could not cooperate. Unable to get rid of the awkward atmosphere with Yukari, Rock wanted to duel with Tonoyama, but an accident occurred during the confrontation. Despite this, Rock did not lose his fighting spirit, so Tonoyama, who was impressed with his spirit, made a concession. In addition, Tonoyama's story clears her misunderstanding when she learns that Yukari couldn't cooperate for the volleyball match.

　　After that, many girls appear and various disturbances and incidents occur, but at the end of the story, Rock says he wants to see more Japanese schools and gain experience, so he leaves Salvia Academy and the story ends.