A threatening letter arrives to female teacher Ashina, who has had sex with a male student Shiina secretly filmed, and she falls into the abyss of lust. Higashikawa, a male student who has been voyeurizing Ashina for a long time, forces her to have sex only once with a promise not to fall apart. Higashikawa, a busty nipple enthusiast, makes Ashina drink an aphrodisiac that makes her nipples abnormally sensitive, and begins caressing her nipples with her fingers, tongue, and toys. The nipples that have been blamed are developed sensitively enough to immediately cum and continue to be erected all the time. Ashina's one-day promise is broken, but she has no choice but to accept it. In the end, she became an uncontrollably lewd teacher who wanted nipple acme from herself...