Shin-hye, Mi-yeon, and Hae-young are three vivacious women who help each other through the tangles of their romantic lives, from tentative first dates to Viagra-taking husbands and one-night stands. Being 40 proves that they're not past their prime.
| Actor | Role |
|---|---|
 Uhm Jung-hwaJung Shin-hye | Jung Shin-hye |
 Moon So-riJo Mi-yeon | Jo Mi-yeon |
 Cho Min-sooLee Hae-young | Lee Hae-young |
 Lee Kyung-youngChoi Seong-jae | Choi Seong-jae |
 Lee Sung-minLee Jae-ho | Lee Jae-ho |
 Lee Jae-yoonHwang Hyun-seung | Hwang Hyun-seung |
 Jeon Hye-jinKim Soo-jung | Kim Soo-jung |
 Choi Mu-sungLee Seong-wook | Lee Seong-wook |
 Kwon Hae-hyoRepresentative Park | Representative Park |
 Jin Sun-kyuMr. Kim | Mr. Kim |
 Jo Woo-jinChoi PD | Choi PD |
 Lee So-yoonSe-young | Se-young |
 Chang Hang-junSecretary Kim (voice) | Secretary Kim (voice) |