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.

It's summertime, and the students of Midorigaoka Academy are indulging in the time-honored tradition of a test of courage! A walk through a "haunted woods," it beats the heat by chilling the blood and forms bonds of friendship through shared terror. It's the perfect activity for Mafuyu! But not everyone joining the fun has pure-hearted revelry in mind--some mysterious villains are using the test of courage as a cover to attack the Public Morals Club!