Leona Hachitani, a female detective from the Special Investigations Division, has been tracking the criminal Oni-Gumo when her superior, Chief Inukai, is murdered by weapons dealer Takada. Leona and her partner—and lover—Samezaki capture Takada, but he is then killed by Oni-Gumo. Leona pursues Oni-Gumo alone, unaware that the criminal is a woman. Falling into a trap, she is captured and subjected to intense sexual torture. Repeatedly brought to orgasm, she is eventually released—but now tormented by the fear that her body has been altered to respond only to women. She calls Samezaki for sex, but finds she can no longer feel pleasure as before, leading to a bitter breakup. Oni-Gumo then turns her attention to Samezaki, ensnaring him as well. Having lost everyone she loves, Leona confronts Oni-Gumo once more, only to be captured again. She is cruelly tormented, her body smeared with saliva, brought repeatedly to the brink of climax and denied release, enduring a living hell that breaks her mind and body. In the end, however, she achieves a happy resolution.