Title: Dine With a Vampire
Sooin spends every day living in utter hell. He lives in a world stuck between guilt and rage, love and vengeance, and complacency and revenge. The best he can do on a day-to-day basis is to try not to anger his roommate, Sungha. Why Sungha? Because Sungha spends every day torturing and beating Sooin because Sooin fell in love with him. Sooin could leave, but his guilt won't allow him to, as he feels his love for Sungha has turned him into a monster. So he endures Sungha's cruelty, but not without hoping that someday he can escape.
Then, while at work, Sooin meets another kind of monster. He runs into the owner of the restaurant he works at, Chi-hwan, because of a cut on Sooin's finger. It turns out that Chi-hwan is a vampire, but not just any vampire. Instead, he is a vampire that can't drink human blood and must subsist off the hearts of his fellow vampire brethren. But for some reason, he is drawn to Sooin's blood, and when he gets a taste of it, he finds it perfectly palatable when human blood hasn't been for so long.
Desperate to ensure Sooin stays alive and well so he can partake in his blood, Chi-hwan makes him an offer Sooin can't refuse. Chi-hwan will kill for Sooin, including Sungha. All Sooin has to do is give him blood.