Title: Welcome to the Café of Love
Ingyu is an incubus. He survives off of the vitality of all manner of beings by having sex with them. Unfortunately, due to the barrier created by the divine beings around humanity's world, Ingyu is limited to the beasts and monsters that live in Devildom to get vitality. It's often gross, painful, and dangerous, and Ingyu longs to get vitality from humans. So, one day, he finally takes the plunge. He ends up getting a chance from the ruler of Devildom to break through the barrier and live among the humans. Thanks to the fallen divine being, Taegyu is able to move through the barrier and protect Ingyu.
Once in the human world, Ingyu wastes no time getting his vitality buffet going by opening up a late-night café. He charms the coffee lids, so when unsuspecting customers take a sip, he can take the form of the one they want the most and take his time sampling them before sending them off as if they had just woken from a dream. All of this is routine until Ingyu encounters Kangin. Kangin is a tired and overworked office drone, and one of his few comforts is coffee. He is precisely Ingyu's type.
Unfortunately, Kangin isn't that easily charmed, as every attempt Ingyu makes to charm him fails. Sure, Ingyu could just move on and charm the next passerby, but he doesn't want just anyone anymore. He wants Kangin, and he's determined to get him. Even if he gets a taste, though, will that be enough? And if it's not, what happens to a human that gets targeted again and again by an incubus?