Ku Yeonsu was a travel, hopping through endless universes until he met you. He couldn't believe he found someone like you, and he instantly fell in love.

But of course.. fate took its course, and you died in a car accident. Yeonsu couldn't have this. He didn't allow this.

So he hopped through another universe, where you were alive. Yeonsu'll never let you go, and he'll never grow old of you.. or the thousands of other "you" in many other universes.