The world is divided into three realms; the human world, heaven; the home of Angels, the holy vessels of God, and hell, where the Demons lies. 

Unlike Angels and Demons, humans are not aware of other creatures' existence. They were just labeled as myths in the human world although those myths are partially correct about the beings of the two. 

Although both are supernatural beings, they have different purposes for existence. Angels' are the servant and messenger of God, their job is to guide and protect humans. Meanwhile, Demons' goal is to lure humans into thinking that they can grant any wish they desire and eventually consume their souls.

" Kang Seulgi, 20, orphan " Irene murmurs as she watches the girl named Kang Seulgi, the last soul she has to consume in order to get her promotion.

Irene is a first-class Demon. She's respected in the field for she has been consuming humans' souls for decades and she's darn good at doing her job.

Hell works like the human's society, they have their own hierarchy. The difference is, they don't base on money or power, they base on the number of souls they have successfully consumed. 

" ya," Irene nearly jumped out of the bush she's hiding in when someone suddenly appeared beside her " what? You looked like you've seen a ghost " Joy giggled, she's Irene's colleague. She's a demon like her— a seductive one to be precise.

Joy is one of those demons who uses her charm to lure humans. She works perfectly with old geezer and erts with nasty desires. No mere human can resist Joy's charms.

" you almost killed me " Irene glared.

" We can't die, we're immortals and why would I dare to try and kill such a highly Demon like you? I'm not out of my mind " Joy shakes her head " by the way, is your client here? Why are you sitting and hiding behind these bushes as if you're a criminal? " she asks.

" None of your business " Irene rolled her eyes.

" can't you be more friendly? We haven't seen each other for years! " Joy exclaimed. 

Irene went back to hell after fulfilling her previous job and a day in hell is equivalent to a couple of years in the human world. Hell and heaven don't have a concept of time unlike in the human world.

" so, who's your client? She's your last client before getting promoted, right? " Joy continued " you've already consumed 666,665 souls. I'm getting envious, I want to get promoted as well " she sighs.

Devils who've successfully consumed 666,666 souls will be granted a promotion. In human terms, it's like retirement because promoted Devil won't ever need to work and consume souls if they choose to, they could just laze around in their own realm.

" if you just work properly instead of playing around, you'll get your promotion in no time "

" consuming nasty humans' souls without a little game isn't too fun you know " Joy shrugs. She's a sadist.

Irene gave Joy a disgusted look and stood up, wiping off some of the dirt that has gotten into her coat " I'm busy, get lost now " she shoos away the girl.

" Alright, alright " Joy surrenders " oh, just a heads up, Angels are kinda killing our vibes these days, they get too much involved in our business. I don't know what has gotten into them " she annoyingly shakes her head.

Angels and Demons aren't exactly in friendly terms but they aren't in such bad terms where they would lay a hand with each other. Angels aren't fond of fighting and Demons knew that they are no match to heavenly beings. Fighting would just stir up imbalance to every realm and will create havoc so they don't even think about it. 

" Well then, I'll get going now, see you around! Ciao " and in a snap of a finger, Joy disappeared.

Demons lure humans by fulfilling their desires— whatever it may be, money, power, or honor. They make humans sign a contract, the fulfillment of their desire in exchange for their souls. There has to be a desire for a soul to be devoured, a soul without a desire is inedible. 

Once the contract is signed, there's no turning back and that's what Angels want to prevent from happening.

Angels make sure that humans would not be tempted by their desires and not end up signing a contract with a Demon. Angels could meddle with their negotiation but once the contract is signed, they cannot do something about it anymore and they have no other choice but let the Demon take over.

" Seulgi " Seulgi's professor approached her.

" oh, good afternoon ma'am " she politely greeted the middle-aged woman.

" you did a great job writing your essay, are you sure you're not interested in joining the competition I've mentioned? " Seulgi politely rejected her professor once again. 

" that's a shame, I bet you'll win an award if you enter that competition. Oh well, in case you change your mind, you can always visit me in my office " 

" Okay ma'am, thank you " Seulgi slightly bow her head down and when her professor left, she continues to wal