The Ghost, My Love (2014)

Nammon's parents passed away in an accident. She has a younger brother she has to look after on top of going to school and such. Pee is a wandering soul who needs help. He's not dead, but his body is in a coma somewhere. He comes to ask Nammon for help so that he can return to his body. However, he doesn't really remember or know what happened to him, but Nammon is the only one who can see him. They eventually fall in love and overcome obstacles together.