It's Mine(2018)

It's Mine

There’s nothing that Yo-Han Do doesn’t know about his crush, Da-Jeong. Where she sits in class, works after school... and even where she lives. But unable to approach her, he watches her every move from afar and will do anything to protect her. Anything.

"What can I do to get closer to you?"

Today, just like yesterday, Yo-Han Do is watching.

(Source: WEBTOON)