Megumi Harutogi, a special agent working for the National Education Bureau, leads a double life—by day, she pretends to be a loving wife in a sham marriage, and by night, she becomes the masked warrior "Mōretsu Mask," fighting corrupt teachers while completely naked. To uncover the conspiracy lurking within Goumon Academy, she must even deceive her loyal husband. However, the evil teacher Amakuru Taku discovers her true identity and sets a trap, capturing Mōretsu Mask. Under brutal torture, the masked warrior is forced to reveal all her secrets.