Chinatsu's Voice

The series takes place at a certain Japanese location where a girl moves in with her aunt to a new house after experiencing some more or less shocking event back home. There she meets a boy named Fuyuki who she from then on spends a lot of time with. The thing special about Chinatsu is her voice, a voice which many seems to have heard before, but from where? What's so special about this girl and what'll happen in the future?