Clannad

Tomoya Okazaki is a third year student labeled as a delinquent. Everything seems to be unchanging for his school life until he meets Nagisa, and then Tomoya finds that his life is about to change. He starts to have dreams of a bleak world and meets a girl who has the ability to fuse junk together in order to create things, and in doing so, creates a body out of junk for him. He is then reborn into this empty world and follows around the girl, the only two existences who are "alive."