Charon Ishihara is a minor character from the New Dominion Tank Police OVA, appearing in the second episode. She was an officer with the Osaka Police Motorcycle Division and was partnered with Leona Osaki before the latter's transfer to the Tank Police.
Some time after Leona joined the Tank Police, Charon took part in an undercover investigation into the Dai Nippon Gaiken Research Corporation. The hi-tech arms manufacturers were suspected of several illegal activities and Charon posed as a new employee for the company in order to infiltrate them and expose their crimes. However, Charon was found out and Dai Nippon Gaiken sent their agent Mueller to eliminate her. Mueller pursued Charon to an empty parking complex and cornered her. Charon fought back, but Mueller's cyborg body didn't react to her attacks. Mueller then strangled Charon to death.
Fortunately, Charon was avenged by her old partner Leona who, against orders from the Chief, pursued her own investigation against Dai Nippon Gaiken. While she wasn't able to blow the whistle on the corporation, she did manage to identify Mueller as Charon's killer and had him arrested.