A gang of young thieves try to rob a mob boss, but their heist is interrupted by an officer of the Tokyo Police Department's elite Zero Division. They get away with the loot, but the officer, a beautiful, more-than-slightly psychotic young woman who also happens to be an excellent shot, is tracking them down. To bring the case to a successful conclusion, she must deal with rival crime gangs, small- time crooks, and the wavering loyalties of her own partner.