A sexual scandal between a math teacher and a student in a prestigious high school ended in tragedy. 4 years later they meet again, now as 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.
It's the story of a mother who died and begins a 49-day long project of reincarnation, and a husband who has barely begun to live a new life after overcoming the pain of losing his wife.
Jo Kang Hwa is a skilled thoracic surgeon. After losing his wife four years ago, he had been working as a single father until he got married again two years ago. While he seems like a caring person, he does not offer a hand nor intervene when needed.
