When Ashina, a female teacher who was secretly filmed having sex with a male student, Shiina, receives a threatening letter, she falls into the abyss of lust. Higashikawa, a male student who has been secretly filming Ashina for a long time, forces Ashina to promise to have sex only once, with the promise not to reveal anything. Higashikawa, a big-breasted nipple enthusiast, makes Ashina drink an aphrodisiac that he bought online that is said to make her nipples abnormally sensitive.