Seo In-woo unexpectedly falls in love with In Tae-hee, a fellow student at the same university, when she asks to share his umbrella in a rainstorm. It is love at first sight for In-woo, and they start dating after only a couple of weeks. Tae-hee dies suddenly when she is hit by a car. 17 years later, In-woo is a high school teacher, married with a child. He starts to notice similarities between a new student of his, Hyun-bin, and Taehee. In-woo struggles with the concept of falling in love with another man, and they get bullied by students at the school for appearing to be homosexual. They overcome their fears with the realization that Hyun-bin is Tae-hee reincarnated, and they are eternal soulmates.