A crime thriller about a man who spent a night with a strange woman who doesn't even know his name before getting married.

Daechi, the place with the most enthusiasm for academia in Korea. 'Yunim' who once dreamed of becoming a novelist lives out her life as a Korean instructor in Daechi. However, on the day the midterm exam is about to end on the middle school where Yunim is in charge of, the teacher of that school comes visiting Yunim. The schoolteacher 'Kihaeng' is Yunim's ex-boyfriend 10 years ago. Now, the two becomes the topic of gossip among the parents of Daechi.