Seven years after marriage... Nana and her husband Toru's "non-restrictive relationship".Their marital relationship begins to fall apart when Nana starts working at a certain art class.Nana is asked to become a nude model for one of her talented students, Kozuka.A few days later, Kozuka sees through Nana's "desire to be bound" deep in her heart and will be tied up with her rope.The moment the rope bites into Nana's transparent white skin, a certain feeling that she has never experienced before begins to sprout.