Miki, a beautiful and athletic female student, transforms into the sailor-suited warrior Sailor Athlete. She infiltrates a school in search of crucial clues about the demon king from the underworld, but students and faculty who have sold their souls to demonic forces attack her. Transforming into her warrior form, Miki defeats her enemies with overwhelming power. However, Ganibel, a priest from the demon realm, corners her using tentacles as weapons. The tentacles wrap tightly around Miki's toned body, crushing and violently assaulting her. She loses consciousness, bound by the writhing appendages, destined to surrender her soul to the demons. The tentacles tear through her sailor uniform, squirming across her flawless skin and stimulating her against her will. Her body betrays her, responding repeatedly despite her resistance. The tentacles penetrate deep into her warrior's vagina, forcefully injecting thick semen. Gradually, Miki's body and mind spiral into madness. The once-proud warrior succumbs to evil, selling her soul to the demonic horde, moaning lewdly and spewing filthy words as her beautiful face is drenched in a heavy load of cum—finally falling into depravity. (Bad End)