A live-action version of a masterpiece doujinshi that has become a hot topic on SNS and has accumulated over 60,000 downloads. A heartrending erotic drama depicting the pure love of an older sister and younger brother. My active older sister suddenly stopped going to school and changed. She sees her sister who can't do anything, and her brother gives her a role. It was to have sex with my brother. At some point, the brothers and sisters begin to develop a forbidden love for each other.