Read Kikenchitai Danshi - Kedamono Black & White Manga Online
From JShoujo Scans:
High school girl Kurei-chan attends a school that is located near two other high schools. The other high schools are famous for their gang leaders, the Black leader and the White leader. One day after going to the market, Kurei-chan decides to jump a wall to enter the school faster. Unfortunately, she jumps in the middle of a fight between Blacks and Whites. Of course, they are all attracted to her--she is a girl after all! Kurei-chan tries to defend herself by throwing tomatoes at them, but her effort just makes them more upset! Her hero appears on a bike. He is Kuroki-kun, the Blacks' leader and he is there to save her. A link has already been developed between those two. But the white leader has watched everything from behind, and a new game has started: Kurei-chan is the new target!