Red Strings Under The Moonlight summary:

Yue Lao is the God of matchmaking who is tasked with tying all manners of god, spirits, demons, beast, and humans together with their fated significant others with the Res String of Fate. It is a job that allows no room for errors.

Awaking from a drunken slumber, Yue Lao finds himself in a peach blossom grove with no recollection of the night before, but more important, he finds a Red string tied around his wrist. On the other end of the string is the equally drowsy and confused warrior God Er Lang Shen. Neither of them know what happened the night before or how they ended up here, but Yue Lao doesn't care. He has a goal, and that goal is to find a way to untie this red string as fast as possible, come hell or high water.