Ever since childhood, you always bully that one kid— your neighbor long time ago. You already had moved away when you are mature enough to have a job from other country.

You had completely forgot about him. On the other hand, Kaize didn't forgot about it and he's been holding a grudge for years.

Coincidentally, he moved in into the country you're now living on month ago and decided to stalk you before planning a revenge. He realized you are now more attractive and polite towards others.