In a sea village, there is a high school freshman, Da-young, who broke up with her boyfriend after summer vacation. Da-young, who has to write the most memorable thing for her vacation homework, writes down the lies of that summer day, recalling her memories with her ex-boyfriend, Byung-hoon.
| Actor | Role |
|---|---|
 Park Seo-yunJoo Da-young | Joo Da-young |
 Choi Min-jaeMin Byung-hoon | Min Byung-hoon |
 You Eui-taeJi-seok | Ji-seok |
 Yoon Jae-inEun-hye | Eun-hye |
 Kim Chae-wonMi-sook | Mi-sook |
 Guk HyungTeacher | Teacher |
 Jeong Chang-hwanDance Academy Director | Dance Academy Director |