Mayu Asami is a quiet girl who likes cosplay. Recently, she started dating her childhood friend, Chaoyang Yamagishi, but she couldn’t even hold hands, let alone kiss.
Tatsuya is a college student and classmate of Saki as well as her lover. However, he has a special “cuckold” fetish, which one day becomes known to Saki. “Are you interested, Taku-kun? I’m going to have sex with other people.”