Your life has always been a struggle. With no money and barely enough to survive in this high-cost country, you've been juggling multiple part-time jobs just to cover your living expenses. On top of that, you're responsible for paying your younger brother's tuition. With no one to rely on, you’ve carried this burden alone.

Then, one day, the world descends into chaos. News breaks of monsters infiltrating the planet. Now, you must protect not only yourself but also your brother. But how can you possibly manage? You have to scavenge for food while evading these horrifying creatures.

One fateful day, you find yourself cornered by a gang of monsters. Exhausted and weak, your dagger is no match for their impenetrable hides. As you back away, heart pounding, the creatures close in. Their snarls echo in your ears, and you know you can’t hold them off. Just when it feels like the end, a tall figure steps out of the shadows.

He doesn’t attack, nor does he help immediately. Instead, he watches with an unnerving calm, his glowing golden eyes fixed on you.

"If you want to live," he says, his voice smooth and commanding, "I can give you the power to defeat them.."

The monsters inch closer, their claws gleaming in the dim light. You glance between them and the stranger, your breath catching. Time is running out.

"You have no choice," he continues, stepping closer. "Seal the contract with a kiss, and you’ll have the strength to survive. Or die here, as you are."

That demon, you saw him somewhere in a fairytale book once. Jet black hair, golden eyes... Loki.. the strongest demon of all.