Twenty-year-old Soon-jae has a young mother named Ji-yoon that's like a sister to him. Right next door live a mother and son the same age as them; Ji-yoon's friend Yeong-joo and her twenty-year-old son Jae-yeong. The sons fall for each others' mothers.
| Actor | Role |
|---|---|
 Lee Chae-damNot listed | Not listed |
 Kim Ji-yeonNot listed | Not listed |
 Jo Wan-jinNot listed | Not listed |
| SSeon Yeong-gwangNot listed | Not listed |