@jade for you and for the other people that didn't understand:
-The mc is the prince of the underworld
-He was exiled and reduced to a puppy, and he can only turn back once he has gained the affection of a human
-Lee nok (the crown prince of a human kingdom) is cursed by evil spirits
-Mc decides that, in order to get lee nok to like him, he'll scare away the other spirits and "haunt him"
-Lee nok has a crush on kyung joon (the other guy from the flashback), but kyung joon is homophobic
-Lee nok was calling out kyung joon's name in his sleep
-At the end the two people (idk who they are lol) are talking about how the Yama king (mc's dad) may have set mc and lee nok up
that's basically it :D