The secret story of the sexiest and youthful sisters that can not be revealed! The confidential secret of the boyfriends who reveal is revealed. He is a sister. Sukyoung is between Sangwoo and Jinhee and loving each other. The two of them talk about their lover, and when they accidentally find out that their boyfriends are high school alumni, they ask about her sister's boyfriend ...
| Actor | Role |
|---|---|
 Do Mo-seNot listed | Not listed |
 Jo Wan-jinNot listed | Not listed |
 Jo Yong-bokNot listed | Not listed |
 Oh Ji-hyunNot listed | Not listed |
 Sang WooNot listed | Not listed |
 Yoo Sul-youngNot listed | Not listed |