Koo Gwang Soo (Oh Jung Se) is 39 years old. He was once the brilliant PD (production director) of the nation’s top live music program. But his fall from grace occurs when members of an indie band he’d cast drop their pants onstage and flash the entire country during a live broadcast. Gwang Soo loses his position and gets shunted to another program, spending the rest of his professional life in obscurity. He is desperate to get married, but his workaholic ways leave him little time to date. Gwang Soo often thinks about “the one who got away,” his ex-girlfriend Joo Da In (Yoo Da In), who suddenly broke up with him one day and left him heartbroken. When they meet again, Da in is a single mother whose life revolves around her young daughter.

Kang Jin Goo (Kim Young Kwang) is 29 years old. Fashionable and smooth, he is a tour planner for a large vacation travel agency. Jin Goo has been carefree for most of his life, but he faces a rough patch as he turns 29 and starts having to reevaluate his whole future. He has a coworker, Ma Se Young (Kyung Soo Jin), who’s from a small town, is outspoken and rough around the edges but a loyal friend.

Kang Min Goo (Yook Sung Jae) is 19 years old. He is a hot-tempered high school senior and judo athlete. Min Goo dreams of going to his dream college on a judo scholarship, which means giving his all to win a gold medal in his competitive matches. Min Goo keeps running into a cute but mysterious girl named Soo Ah (Park Cho Rong) all over town, and he decides that they’re fated to be together. But Soo Ah has the entire district’s high school boys swooning over her.

Kang Dong Goo (Choi Ro Woon) is 9 years old. He is a child actor who got famous doing food commercials because of his healthy appetite. Dong Goo suddenly feels threatened when, for the first time ever, he loses a job to a new rival child actor. The precocious Dong Goo has also been secretly dating 8-year-old child actress Jang Baek Ji (Lee Chae Mi) for the past two years.