Gantz is Justin's childhood rival, while appearing rougher and meaner than Justin, they both enjoy daring or duelling with each other to prove who is greater.
Gantz has his own small gang consisting of Goose and Kozuru as well as sometimes including his younger brother, Tentz.
Gantz and Tentz live with their mother in a house close to the Port of Parm. Gantz has an older brother in the Garlyle forces called Gontz.
Gantz makes an appearance as a playable character in Grandia Parallel Trippers and can be recruited after the events of the Sky Isles. He can wield sword, axe or projectile based skills and can only possess monster skills but no formal form of magic. He is extremely weak and has the lowest combined stat total of any player character in the game.