It's been 7 years since I got married ... Nana and her husband, Toru, have a "non-binding relationship". The relationship between the two couples begins to break when Nana starts working in a certain art class. Nana is asked to become a nude model for one talented student, Kozuka. A few days later, Nana was tied up with a rope through Kozuka's "desire to be bound" at the bottom of her heart. At the moment when the rope bites into the white and transparent skin, a feeling that I have never experienced before begins to sprout in Nana.
