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.
| Actor | Role |
|---|---|
 An So-heeYun-im | Yun-im |
 Park Sang-namKi-haeng | Ki-haeng |
 Lee Hyun SoJong-won | Jong-won |
 Takuya TeradaMichio | Michio |
 Jo Eun-yooNa-eun | Na-eun |
 Oh Tae-kyungManager | Manager |
 Bae Yu-ramDong-hwa | Dong-hwa |
 Shin So-yulYu-jeong | Yu-jeong |
 Go Seo-heeHye-rin's mother | Hye-rin's mother |
 Yoon Jun-wonDetective Joo | Detective Joo |
 Kim Tae-junDetective Park | Detective Park |
 Jung In-giVice manager | Vice manager |
 Jang Jun-wheeVice head teacher | Vice head teacher |
 Lee Jae-inHead teacher | Head teacher |
 Yang Ji-ilInstructor | Instructor |
| KKang Hyuk-ilJin-do | Jin-do |
 Hong Ji-youngYeon-woo's mother | Yeon-woo's mother |