Hana and Tetsuya, who had been childhood friends living in the neighborhood since forever, became siblings when their parents got married. Feeling lonely after suddenly becoming family and finding a wall between them, Hana reminisced about the past and initiated a game of 'doctor'. She was surprised to see that Tetsuya's penis was unexpectedly large. Intrigued, she proposed playing 'doctor' again and let Tetsuya touch her massive breasts... From that day on, she became the outlet for her younger brother's uncontrollable sexual desires...
