Mourning Grave

Sonyeogoedam is a movie starring Kim So-eun, Jeong-tae Kim, and Hye-Rin Han. A teenager, with the ability to see ghosts, returns to his hometown to face his demons.
A boy who can see ghosts moves to a small town, where he befriends a female ghost. The two work together to investigate a masked ghost who is murdering students one by one.