Kanon Ichikawa plays the role of a seemingly sweet and innocent little sister, adored by everyone for her cute, petite appearance and friendly demeanor. In reality, she looks down on her older brother, mocking him as a naive virgin and pretending to be the perfect girl while hiding her true self. Everything changes when she accidentally discovers a surprising side of her brother and experiences his incredible skill firsthand. From that moment on, their relationship takes an unexpected turn—she begins to truly understand him, indulging in his talents again and again, climaxing repeatedly under his expertise. A shocking transformation unfolds as the sibling bond shifts into something far more intimate and intense.