it's been seven years since i got married... Nato's husband Toru's "unbounded relationship". The couple's relationship begins with Nana starting to work in an art class. Nana is asked to become a nude model for Otsuka, a talented student. A few days after that, Nana's desire to be bound in the depths of her heart was passed through Otsuka and tied with a rope. The moment a rope eats into the white transparent skin, one emotion that has never been tasted in nana begins to sprout.