Seong-min is a married father who retired from the company and opened a bookstore with his wife After Ga-hee, a very beautiful ballet teacher, arrives at his shop, Seong-min starts thinking about her every day. Ga-hee is only with her current husband because of her mother's hospital bills Being in a relationship, her relationship with her husband is cold, and her relationship with Seong-min is getting closer every day. So both of them fall madly in love and become irrational and what happens next.