Yeong-nam, an exam instructor, faces challenges after a student's death due to exam stress. He embarks on a journey to teach elementary school kids despite battling cancer, highlighting struggles and triumphs in education.
| Actor | Role |
|---|---|
 Uhm Tae-woongKim Yeong-nam | Kim Yeong-nam |
 Park Sang-myeonVice Principal | Vice Principal |
 Jeon Soo-kyeongPrincipal | Principal |
| YYun Hyun-sukPTA President | PTA President |
| CChoi Yi-naNot listed | Not listed |
| NNam Dae-hyeopNot listed | Not listed |
 Hong Jeong-minEun-bi | Eun-bi |
 Lee Jae-junJoon-soo | Joon-soo |
| CCho Jae-youngChang-il | Chang-il |
 Im Han-binNot listed | Not listed |
 Han Chang-minNot listed | Not listed |
| DDoyeonNot listed | Not listed |
 Lee Seong-jongNot listed | Not listed |