Kim Da Hyun is a young and sincere middle school teacher, who has little interest in money. She is also extremely warm-hearted and loves to help other people. When she helps carry an elderly man's belongings from the train to another location, the elderly man is extremely thankful. This grandfather turns out to be the extremely rich owner of a well known conglomerate. His grandson, Lee Jae In is a quick-tempered businessman who rivals his grandfather, but in an almost comical way. In an order to "tame" his favorite grandson, the grandfather agrees to give his entire fortune to the person who marries Kim Da Hyun, therefore forcing Lee to meet the girl whom his grandfather chose. Although at first Kim and Lee don't get along because of Lee's extremely cute but bad temper, their arguments bring them closer together. Lee starts to get jealous when Kim's fellow teacher starts liking her too. Through the clever conditions that Lee's grandfather makes, Lee starts a relationship he does not look forward too. However, what looked like a relationship that would 99% not work out, turns out to be the "perfect" match, the 1% chance.