Kang, Hye-soo: Starring U-IE from “After School”

A single mom with a 9-year-old daughter. Her husband died prematurely and left her with unpaid debts. Her life is a constant day-to-day struggle. One day, she learns that she has a brain tumor and it throws her into despair for the first time. But then she is approached with a strange proposition that if she agrees to be the legal wife of her boss for just three months and donate a part of her liver to his mother, then he would give her a sizable amount of money. She seriously considers and accepts the offer in order to leave her daughters with a legal guardian.

Han, Ji-hoon: Starring Lee, Seo-jin

He was born in a life of comfort and luxury, as the second son of the chairman of the largest distributor in the nation. He has a burning ambition to leap ahead of his half-brother to take control of the vast family business. Because he was a love-child, he has a strained relationship with his mother. But then his mother fell into critical condition and is now in need of a liver transplant to survive. However, because no one could voluntarily donate a part of their liver to her unless the doner is a family member, he offers a marriage contract to Hye-soo, one of the assistant cooks at his restaurant, who can be a donor match.

Seo, Na-yoon: Starring Kim, Yoo-ri

The only daughter of a family that owns a distribution company, who has grown under her parents’ roof with everything rigorously planned for her entire life. When she realized she couldn’t live up to her parent’s wishes to become a world-class musician she found her confidence shaken. Then, she meets Ji-hoon., and they are both attracted to each other and could relate to each other’s past experiences. But when her parents finds out about their relationship, they could not stay together any longer. A few years later, she is engaged to Jung-hoon who happens to be the brother of Ji-hoon. However, when she then hears that Ji-hoon is also getting married, she feels betrayed even though herself is going to get married soon.

Han, Jung-hoon: Starring Kim, Young-pil

Ji-hoon’s half-brother and the eldest son in the family who has taken over the reins of the family business and makes all executive decisions. Unlike his charismatic and business-savvy dad, he is impulsive and wastes time on pursuing miniscule profits, driving the company to the ground. His first marriage ended in a divorce, and days before his second wedding, he learns that his fiancée, whom he passionately pursued, is in love with his brother. This consumes him with jealousy and he decides to destroy Ji-hoon completely.

Park, Ho-joon: Starring Kim, Gwang-gyu

He is a good friend of Ji-hoon and they even played in a band together since young ages. When the company he worked for started to flounder, he got a call from Ji-hoon asking to work together. So he accepts the job as a restaurant manager. He is generous and understanding but Ji-hoon criticizes him for being too passive and timid. As a loyal friend to Ji-hoon, he helps Ji-hoon and Hye-soo keep their pact under wraps.