It's not manga, first of all, but it does take place in Japan. It follows Katie, who got moved there willy-nilly to live with her aunt after her mother's death. Not only is she grieving and lonely, she feels out of place, a tall blond American who barely speaks any Japanese and can't quite grasp all the different subtleties of life in a new country.
Then she meets Tomohiro Yuu. One day he's a jerk, dumping his girlfriend in the most callous way possible. The next he's a sensitive artist, creating drawings that almost seem to come to life. Wait . . . they are coming to life! What exactly is Yuu, and what does Katie herself have to do with his mysterious abilities?
If you are a die-hard Japanophile, pick up this book to become immersed in everyday life in Japan, with a little magic, mystery, and romance thrown in.