On the train, strangers touch him because of an aphrodisiac... and his best friend does too...!? Aoi, a straight university student popular with women, earns the resentment of a woman named Mei and is made to drink an aphrodisiac. According to Mei, it's "an aphrodisiac that makes both the one who drinks it and the people around them hot and horny." Still half-doubting her, Aoi boards the train the next day to go to university, only to suddenly feel his body heat up and become aroused. From behind him comes the sound of heavy breathing. "Could what Mei said actually be true!? Is the aphrodisiac making a stranger get hot and horny because of me... !?" But the one getting excited behind him isn't a woman -- it's a man. A stranger in a suit starts touching him, touching even his genitals. Other men who had been watching join in, fondling his nipples and even his anus, until he's on the verge of climax -- when his best friend Taiki comes to the rescue. Telling Taiki, "I'm not feeling well, so go on ahead to campus while I stop by the bathroom," Aoi slips away... but for some reason, Taiki follows him into the stall, kisses him, and starts touching him...