|Graduate school student Jung-In and Hwan-Yoo are truly a match made in heaven. Their fateful first encounter begins when Hwan-Yoo chases a train boarded by Jung-In after he picks up the wallet she dropped at the train station. As their relaionship develops, Hwn-Yoo chooses between marriage and studying overseas by flipping a coinl the resul, marriage. Their life together, which seemed to be so full of promise, is cut chort by Hwan-Yoo's death. Jung-In is left behind to endure life alone, without Hwan-Yoo. As the onset of unbearable loneliness closes in on her, Jung-In receives a letter.