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 he bought online that is said to make her nipples unusually sensitive, and begins caressing her nipples with his fingers, tongue, and toys. The nipples that have been tortured are developed to be sensitive enough to cum immediately, and they become constantly erect. The one-day promise is reneged on, but Ashina is so depressed that he has no choice but to accept it, and is unable to suppress his lewd lust. She finally becomes a slutty teacher who can't control herself and wants to cum on her nipples...
