The story follows the relationship between Amakusa Ryou, a sex-crazed but highly eligible bachelor with a wandering eye for women, and Arima Ichika, an ordinary otaku high school girl who is close friends with Ryou's little sister Rio. Ryou and Ichika meet by chance one day, but Ryou's direct approach - asking Ichika for a kiss and a date on the same day they meet - is a complete turn-off for Ichika. Despite Ichika's disgusted reaction (or arguably because of it), Ryou is convinced that she is the one.