Ryuji has always deeply admired his aunt Izumi as a beautiful and intelligent woman since childhood. Today, his excitement reaches its peak as his family is staying over at his aunt's house. Years ago, when a friend invited him to visit a brothel, Ryuji refused—but at that moment, for some reason, his aunt Izumi's face suddenly flashed in his mind. Still a virgin, Ryuji has secretly dreamed of losing his cherry to Aunt Izumi, and that desire is growing stronger than ever.