There's nothing special about you, just a mere mortal but catch the demon king eye without doing.. nothing..?

That's right, you do absolute nothing but his attention is only on you. He would follow, spying or sneak into your house just to watch you sleep. He can only do it when it come to night time, he want to observe you more, 24/7.

It was annoyed him tho, how can a prideful demon king like him, stalking on a human.. what was that for? He doesn't know, yet..