A likeable, married high school teacher spirals out of control when a student in his class begins unintentionally reminding him of his doomed first love, which ended 17 years earlier.
| Actor | Role |
|---|---|
 Lee Byung-hunSeo In-woo | Seo In-woo |
 Lee Eun-juIn Tae-hee | In Tae-hee |
 Yeo Hyun-sooIm Hyun-bin | Im Hyun-bin |
 Hong Soo-hyunYeo Hye-joo | Yeo Hye-joo |
 Namkoong MinKim Chul-sung | Kim Chul-sung |
 Lee Jae-yongKwak Yoon-jung | Kwak Yoon-jung |
 Im Jae-geunKim Jin-tae | Kim Jin-tae |
 Lee Beom-sooLee Dae-geun | Lee Dae-geun |
 Kim Min-jaeKim Min-jae | Kim Min-jae |
 Jang Seok-wonCho Jae-Il | Cho Jae-Il |
 Jeon Mi-seonIn-woo's Wife | In-woo's Wife |
 Ki Joo-bongDirector of Student Affairs | Director of Student Affairs |
 Park Cheol-minP.E. Teacher | P.E. Teacher |
 Kim Kap-sooProfessor of Sculpture | Professor of Sculpture |
 Oh Ji-hyeSubstitute Teacher of Korean | Substitute Teacher of Korean |
 Woo Jung-kookCourier | Courier |
 Lee Seok-kuSupermarket Owner | Supermarket Owner |
 Kim Jung-youngEnglish Teacher | English Teacher |
 Hwang Hyo-eunSculpture Schoolgirl | Sculpture Schoolgirl |
 Lee Soo-yong2-5 Class President | 2-5 Class President |