けっこう仮面 SURPRISE (2004)

Studying music at a remote island academy, poor Mayumi (Aki Hoshino) and her classmates fall victim once more to erotic tortures at the hands of their corrupting instructors. Just in time, Kekko Kamen (Misaki Mori) takes center stage with a red mask on her head, nunchakus in her hands, and a song in her heart!