Title:
Pinocchio
Author/Artist: Maru
Publishing Status: On-going at Daum
Scanlation Status: On-going by Easy Going Scans
Year: 2009
Genre: Comedy, Romance, Supernatural, School Life

Summary from MangaUpdates:
Pinocchio is about an average high school girl, Choi Ha Ram, who suddenly meets a ghost while is the only one able to see him! Little do we know about this ghost besides his name Yu Ga On and the fact that he is thought to be dead… The encounter with the ghost seems to be a huge turnover in her average life and to top it off a new neighbour comes along to add more excitement in her life.

There is a prequel to this series titled "One Winter".