An unlucky-in-love woman grows obsessed with finding out the writer behind a series of romantic notes inside the library books that she checks out.
| Actor | Role |
|---|---|
 Bae DoonaJeong Hyun-jae | Jeong Hyun-jae |
 Kim Nam-jinLee Dong-ha | Lee Dong-ha |
 Yoon Ji-hyePark Mi-ran | Park Mi-ran |
 Lim Hyun-kyungEom So-hee | Eom So-hee |
 Yoon Jong-shinYang Ji-seok | Yang Ji-seok |
 Uhm Tae-woongLee Yeong-seok | Lee Yeong-seok |
 Oh Kwang-rokJeong Hoon | Jeong Hoon |
 Lee Hyun-kyoungYoon Sun-ok | Yoon Sun-ok |
 Lee EolPark Yun-ho | Park Yun-ho |
| LLee Hyeon-kyeongHearing-impaired Woman | Hearing-impaired Woman |
| KKim So-yeonHearing-impaired Woman | Hearing-impaired Woman |
 Kwon Oh-joongNose-picking Man | Nose-picking Man |
 Jo Sang-kiCarrefour Supervisor | Carrefour Supervisor |
 Lee BomYoung Hyeon-jae | Young Hyeon-jae |
 Han Jae-dukEngineer | Engineer |
| YYong IhBang Chan-ho | Bang Chan-ho |