The backlash against Osaka Mayor and Nippon Ishin no Kai (Japan Restoration Party) coleader Toru Hashimoto escalated Tuesday over not only his remarks that Japan's wartime sex slave system was necessary but also over comments to U.S. military brass in Okinawa that American soldiers should use more prostitutes.

The uproar began Monday morning when Hashimoto told reporters in Osaka that Japan's wartime sex slave system, which forced thousands of girls and women from around Asia into prostitution for the Japanese military, had been necessary in order to maintain military discipline.

The women "were necessary in order to provide relaxation for those brave soldiers who had been in the line of fire," Hashimoto said Monday morning.