A suspicious report suddenly arrives at the Earth Defense Force: a hospital has been taken over by aliens. No one takes it seriously—except Luna Kishimoto, who senses an ominous premonition. She immediately rushes to the hospital, only to find the Mayour aliens already present. Hailing from the planet Mayour, they have come to invade Earth by studying human weaknesses and exploiting them for total domination. Captured before she can transform, Luna is brainwashed and forced into servitude. The aliens subject her to physical torture and pleasure-based seduction, attempting to break her spirit. Yet as Cosmo Woman, Luna resists their evil, refusing to surrender her will. Still, enduring such torment takes a severe toll on her human body. With her Cosmo Capsule stolen and her strength nearing its limit, can Luna uncover and destroy the Mayour aliens' conspiracy in time to save Earth?