Ai Tokiwa was a student and member of Misuzu Daimon's Angels who had a tragic past - she was raped by her classmates, which caused her grugde against men. As time passed she became a skilled Taek Won Do martial artist, so she will never experience the same things ever again.
She blackmailed Azusa Fuyutsuki after she revomed Fuyutsuki's underwear to exposed her, before Onizuka saved Fuyutsuki by showing Ai's underwear. Way later then she faced her rapists who tracked her down, she tried fight them but she counld't because of her trauma. Onizuka helped her beat them and they were sent to jail right after.