Chaos continued to reign in Nippon Ishin no Kai (Japan Restoration Party) on Thursday as senior party members moved into damage control mode after Osaka Mayor Toru Hashimoto threatened Wednesday to resign as the party's co-leader.

Over the past month, calls have grown within the party for Hashimoto to step down after the July 21 Upper House election, as domestic and international condemnation continues over his remarks in mid-May that Japan's wartime "comfort women" system was necessary at the time, and that the U.S. military in Okinawa should consider using more sex establishments as a way to reduce sexual assaults.

Earlier this week, Shintaro Ishihara, the party's other leader who offered initial support for Hashimoto's views, changed his tune when he realized the damage being done to the party's Upper House election chances. He called on Hashimoto to apologize, not for the comments but for the embarrassment they have caused.