Through the course of their lives, a man and his first love are repeatedly separated from each other because of circumstances out of their control.
| Actor | Role |
|---|---|
 Park Bo-youngHwan Seung-hee | Hwan Seung-hee |
 Kim Young-kwangHwang Woo-yeon | Hwang Woo-yeon |
 Kang Ki-youngOk Geun-nam | Ok Geun-nam |
 Ko Kyu-pilGu Kong-ja | Gu Kong-ja |
 Jang Seong-beomChoi Soo-pyo | Choi Soo-pyo |
 Cha YeobLee Taek-gi | Lee Taek-gi |
 Seo Eun-sooPark Min-kyung | Park Min-kyung |
 Bae Hae-sunSeung-hee's Mother | Seung-hee's Mother |
 Ahn Kil-kangWoo-yeon's Father | Woo-yeon's Father |
 Shin So-yulSo-jung | So-jung |
 Song Jae-rimYoon-geun | Yoon-geun |
 So Hee-jungWoo-yeon's Mother | Woo-yeon's Mother |
 Im Hyung-junMr. Bae | Mr. Bae |
 Kim Hyun-sookMs. Min | Ms. Min |
 Min Chae-yeonBoarding Student | Boarding Student |
 Yoo Hee-jeTaek-gi's Subordinate | Taek-gi's Subordinate |
 Ha JunSeung-hee's Partner | Seung-hee's Partner |
 Lee Joo-ChanStudent | Student |
 Yoon Kyung-hoDetective | Detective |
 Baek Seung-chulPolice Station Detective Squad Chief | Police Station Detective Squad Chief |