Kim Da Hyeon 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 order to "tame" his favourite grandson, the grandfather agrees to give his entire fortune to the person who marries Kim Da Hyeon, therefore forcing Jae In to meet the girl whom his grandfather chose.
Although at first, Kim Da Hyeon and Lee Jae In don't get along because of Lee Jae In's extremely cute but bad temper, their arguments bring them closer together. Lee Jae In starts to get jealous when Kim Da Hyeon's fellow teacher starts liking her, too. Through the clever conditions that Lee Jae In's grandfather makes, Lee Jae In starts a relationship he does not look forward to. However, what looked like a relationship that would 99% not work out turns out to be the "perfect" match, the 1% chance.
(Source: Soompi)
~~ Adapted from the web novel "Something About 1%" (1%의 어떤 것) by Hyun Go Woon (현고운).
