Will You Be There (2016)

Soo-hyun comes across magical pills that allow him to go back and forth in time. 30 years to the past, young Soo-hyun meets future Soo-hyun and learns that his girlfriend will soon die because of him. In order to save her, the two Soo-hyuns try to chance the past together, bur a completely new and unexpected past is formed that leads to a new future.