Mafuyu is the no-nonsense, take-charge and hard-hitting leader of her high school gang. But when she gets expelled for being a delinquent, her mother, fed up with her daughter's wayward ways, sends Mafuyu to an isolated school far off in the country.

Mafuyu is looking forward to a relaxing day at the beach after all the recent commotion at school. But with Takaomi tagging along she should have known better than to expect calm and quiet. He plays rescuer to a couple getting harassed by delinquents and of course makes everything worse. Now Mafuyu has to save her vacation and her teacher!