Genius biology doctor Sadayo Ashizume is conducting terrifying research involving human modification to create monsters. One day, he meets freelance writer Yuka Chigusa through social media and invites her to his private laboratory. Ashizume shows Yuka his secret experiments and then attempts to force her into reproduction, causing her to panic and flee. Immediately afterward, Igor—the monstrous henchman of Ashizume—chases after her. At that moment, a naked heroine wearing a pure white mask, White Mask, suddenly appears. She begins her mission to punish Ashizume—but… [BAD END]