Boy From the Future

Dain and Sihyeon are in the same class, but they are awkward. One day, an unfamiliar man claims to be from the future, and said that he will be her boyfriend in the future. And that man is Lee Sihyeon, her classmate!? Dain doesn't believe the words of the unfamiliar man, but she gradually trusts him each time they met. (Source: MU)