Bloody Maiden: Toomarimiki no Shima

Twelve students from the Naginata club at Fujimigahara Girls' Academy travel to a secluded island owned by their club president. The island is said to have once been a base for ruthless bandits who accumulated valuable stolen goods, some of which are believed to still be hidden there. After their club advisor and two students are killed in violent attacks, the remaining girls find themselves in a dangerous confrontation with a strange, masked assailant.