I bet some of you have played doctor with your older sister, younger sister, or neighborhood girls when you were young, remember that excitement? This young brother and sister aren't satisfied with just doctor play, they engage in daily role-playing as masseuses. Shion, the younger sister, adores her older brother and desperately wants to be intimate with him. To fulfill this desire, she sets up a makeshift soapland in her room. This forbidden tale of incestuous pleasure unfolds as she opens her secret brothel for her brother late at night, after their parents have fallen asleep. They indulge in an all-night session with unlimited shots and every option imaginable until morning.