Colors of Wind

When a Tokyo-based man's girlfriend goes missing he goes into a shell and forgets about her. When he finds out that she is dead he meets her mother who thanks her for being a boyfriend to the girl. However, he soon finds out that the truth is different from the story he was told and he himself has had a hand in the altered version of events. He travels to Hokkaido and there meets a girl who may be someone he knows, but is he the person she knows?