The MC (blue text) is a stalker who's obsessed with a young schoolgirl named Yukino (pink text). He's been watching her for half a year, but one day he decides to confess to her. She, of course, rejects him. It turns out that she has a boyfriend (green text), and they have loved each other for a very long time. However, the MC won't settle for that, and orders a special potion that makes her do what he says. He sprays her with it and takes her up to his room to have his way with her.
Yukino never remembers what happens after she gets sprayed, so she returns to normal when it wears off. The MC continues to hypnotize her with the spray until one day when the spray wears off while they're having sex. The MC forces her to have sex with him and then sends her home. The next day, the MC meets Yukino on the street while she's on her way to a date with her boyfriend. He hypnotizes her with the spray and makes her think that he's her boyfriend. They go on a date together.
On their way back, Yukino's boyfriend catches them and asks why she's with the MC. Because she's hypnotized, she doesn't recognize him as her boyfriend and rejects him. The boyfriend says, "If you say you're happy, then do what you want!" and runs away. The MC and Yukino are now together and she says that she loves him. It seems as if he doesn't need the spray anymore. He get's Yukino pregnant and eventually marries her. The end.