New Neighbours?

Kim Mingyu grew up in an area with a couple of kids living in that area but they are older than him by a couple of years and they would always bully him since his the youngest.

One day Mingyu wakes up to a noise and looks out the window to see the house next door was bought and people were moving in. He saw a teenage boy who looks 16 years old, like him.

That teenage boy is Jeon Wonwoo.

A cold guy that always looks sad, likes to be lonely and doesn't want friends, the complete opposite of Mingyu.