[Welcome to the longest synopsis you'll ever see. MGS's TL;DR: Insomniac college student meets extremely beautiful Dokkaebi and yes of course he (they) sleep(s).]
Choi Woohyeok is a college student whose insomnia has gotten worse recently. After moving into a new place alone, not only is he not able to easily fall asleep, he'd have all sorts of nightmares even if he somehow did, and his exhaustion piles up as a result.
Seeing Woohyeok in such a state, his friends have various worries, such as whether there's a ghost in his place, or if he needed to conduct an exorcism. One of his classmates even told him that a Dokkaebi was said to grant simple wishes, should he offer snacks or find items as an offering to them. Even though Woohyeok waved them off, he thinks back on their words when he goes to bed that night.
He might have told his friends to cut the crap, but seeing that he hasn't been able to sleep well for 2 weeks, Woohyeok is willing to try anything. He takes out a lollipop from his bag and leaves it on his nightstand, making a sincere wish for a good night's sleep before heading to bed.
That very night, as Woohyeok lay in bed, wishing for the sleep that would never come, his head is constantly filled with erotic thoughts. First, he can't even sleep, and now, he's even getting sexually frustrated? That made it even tougher for him to sleep. Suddenly, he feels a hand wrap around his dick, and when he opens his eyes, he comes face to face with an extremely beautiful man. As soon as Woohyeok sees that man, his body became immobile and he loses his mind.
"Ah- So this kind of thing is your kink?
"Wh-What is this!"
"You caused this."
"This right here is your dream."