Lee Yoo Jin

A sexual scandal between a math teacher and a student in a prestigious high school ends in tragedy. Four years later, they meet again, now both adults, to reveal the corruption in school and to regain one's reputation as a teacher. Ji Yoon Soo is a high school math teacher with a bright smile and a positive impression of others. She is a hard-nosed and stubborn person who has to push ahead with the decisions she has made. She is a math geek who loves solving difficult problems and teaches students to purely love math. Baek Seung Yoo is emotionless and has no light in his eyes. He used to be a math genius who appeared on a quiz program at the age of five and surprised the world by solving college-level math problems. He was admitted to MIT at the age of 10 but dropped out at the age of 12, and suddenly disappeared. (Source: CJ ENM)

Son Hae Yeong is the type of person who doesn't want to lose money under any circumstance. While growing up, she had to share her mother's love with others. She often found her partners in relationships below her break-even point. Now, Hae Yeong faces the possibility of missing out on a job promotion at her workplace. To avoid such a loss, she makes a plan for a fake wedding. She recruits Kim Ji Uk to be her fiance. Ji Uk works part-time as a cashier at a convenience store. He is the type of person who can't ignore people in need and tries to do the right thing. He is smooth with every customer at the convenience store, except for one person. That person is Hae Yeong. When she suddenly asks him to become the fake groom at her wedding, he somehow accepts her offer. (Source: AsianWiki)