For Aoi Tsukimisato, who's known to hook up with anyone regardless of gender, the library is the one place where he can relax without being bothered. But, one day, someone dares to set foot in that sacred space... the cheerful and popular Ryosuke Harumasa. Ryosuke is Aoi's polar opposite, and insists on closing the distance between them, to Aoi's chagrin... And so, this unlikely pair?a lonesome playboy and a guy with the personality of a Labrador?start getting into all kinds of trouble in the library!