Croquis Pop (2005)

Blurb:
Da-Il has a new job working for a famous comic creator. It would be a great opportunity ... if Da-Il had any artistic ability. Da-Il fears he’ll never be able to create art, until he meets Mu-Huk, a ghost who takes form based on Da-Il’s creativity. The budding artist soon learns he has the skills of a “Croquer,” someone who has the ability to shape the stories vengeful ghosts by entering the “Dead Zone.” It’s a lot for a young man to absorb, especially when Da-Il learns he’ll be the main character in his boss’ new book - Croquis Pop!

Source: www.anisearch.com/manga/22918