Mary Tachibana, a slender, busty sister who believed her brother's lie, goes wild and pounded in the cowgirl position

The movie revolves around Mary Tachibana, a sister who returns to her hometown after three years, and her interactions with her brother Takashi. The story explores their sibling relationship and the central dramatic tension arises from Takashi's attempts to deceive his sister, taking advantage of her naivety. As the plot unfolds, it delves into themes of trust, manipulation, and the complexities of their bond.