Watch Gantz: O (2016) HD Full Movie Free on solarmovie.do. Watch Gantz: O (2016) online free. After being brutally murdered in a subway station, a teen boy awakens to find himself resurrected by...After being brutally murdered in a subway station, a teen boy awakens to find himself resurrected by a strange computer named Gantz, and forced to fight a large force of invading aliens in Osaka.