Kyung-min is an English tutor who is often pressured by his lover Seon-hee about getting married. He starts giving lessons to a new student Young-won, a piano tutor, and they decide to exchange tutoring like barter. Unlike Seon-hee, she seems to be an untied person when it comes to relationships, which strongly attracts Kyung-min. But as he falls for her, he faces unexpected but familiar situations.
