Hirayama Hayaka’s parents got divorced, and now Hayaka and her mother are looking for a fresh start in a new town. To make life easier for her mother, Hayaka decides to abandon her private school days and enrolls in an industrial high school without touring it. On the first day, after witnessing a fight between her class’s leader and an upperclassmen, Hayaka learns that all the girls in the school transferred out months ago, because the boys were really out of hand and always fighting. Hayaka is the only girl in school! The next day when Hayaka comes to school, the same class leader and his friends adopt Hayaka, and she learns that not all the gansters in school are bad! The class leader turns out to be a caring boy, who mothers all the boys in the class, and then extends his care to Hayaka. As the class leader knows that Hayaka is in danger if she stays unprotected on school grounds with so many gansters around, he puts a metal plate in her book-bag just to be safe. But when a fight e