Although Mariko lives a peaceful life with her husband, she has grown a little disgusted by her unusual sexual fetish. Her playboy brother-in-law Kenta notices her secret sexual frustration... Kenta skillfully taps into the Kokoro that lies deep inside Mariko, and as he seduces her, she is swept away by his fingertips. His delicate yet bold caresses easily melt the walls of her vagina, gradually loosening up her Nana Kokoro and body. Before she knows it, Mariko tells herself, "I was just bullied..."