Calling You?

Haku is a teanage boy who lives in a small town called "obell town", One day his family decided to moved to the city where he can study and improve his magic. While going to the city a monster suddenly attacked them, Because Haku is still weak he can't handle the monster that attacked them, The monster killed him. through Haku's dream he saw a "shadow" which cursed him exchanged of him getting revive.