Jin, a mysterious kid with a halo carved in his hand, and extraordinary fighting skills, lives with his grandfather in a beggar's community. In other place, the old scientist Amagi is searching for professor Kanzaki, to ask him for the whereabouts of the "player" -a kind of genetic altered humans- Zet, which they created some years ago. Soon, Jin and his grandfather are attacked by a mysterious man who turns into a monster.

The connection between professor Amagi and professor Kanzaki, seems to connect also young Jin to the mystery of the "players" and Zet.