Song Jihyo

 Choi Jinhyeok

 Lee Pilmo

 Choi Yeo-jin

While in their early twenties, a medical school student, Oh Chang-min, and a dietitian, Oh Jin-hee, fall in love and marry despite his family's strong opposition.Chang-min comes from a family of wealthy, successful doctors who believe Jin-hee isn't good enough for him, which thus prompts them to cut him off financially after he marries her. In order to earn money right away, Chang-min gives up his dream of becoming a doctor, and instead becomes a pharmaceutical salesman. He is miserable at his job, while Jin-hee's inferiority complex deepens as her husband's family continues to look down on her. They begin to fight constantly and eventually get a divorce. Six years later, Chang-min has gone back to med school to pursue his dream, while Jin-hee has also put herself through med school. They end up as interns at the same hospital, where they'll have to work in the emergency room together for three months.