His first impression was the worst. Nariyuki Kishibe, the best friend of Mamoru's uncle and childhood friend of his aunt, is an unlikable guy who's always frivolous and says random things. Mamoru, who starts to live at his uncle's house since he got into college, is fed up with Nariyuki, who gets worse every time he sees him. However, his heart races when Nariyuki occasionally shows his cool, mature side. One day, Mamoru ends up sleeping over at Nariyuki's place, but why is he getting aroused while they're in bed together!? Nariyuki wakes up and kisses Mamoru, and then they end up taking the next step!