One night while walking back home after being rejected by his boss, Airi Goto, Yoshida comes across a young girl named Sayu Ogiwara who has run away from home. Sayu offers to have sex with him if he gives her a place to stay. He refuses her offer, but ends up letting her come home with him. Instead of doing sexual favors, he tells her that she can do some work as compensation. While living together, she is touched by his kindness and hopes he never throws her out. Sayu lets her true feelings out and Yoshida also admits that he feels she has made his apartment feel cozy and homelike.

The seasons continue to go by until one summer day when a woman named Ao Kanda starts work at Yoshida’s office. Ao is Yoshida’s ex-girlfriend, which makes Sayu feel uneasy. On the other hand, Yoshida is determined to help Sayu see her parents one more time, but he can no longer imagine life without her.