Beautiful wife Aki's sensitive nipples heighten her libido, causing her to lactate—an obscene hidden nature. Her husband's younger brother sees through her secret and assaults her. Though she resists, he torments her nipples, driving her into agonizing pleasure. As she reaches climax, a flood of breast milk gushes out, and she repeatedly succumbs to ecstasy right before her sleeping husband's eyes, overwhelmed by taboo desire. The exquisite interplay between her sensitive nipples and lactation draws her deeper into depravity.