Calls for Nippon Ishin no Kai (Japan Restoration Party) co-leader Toru Hashimoto to resign mounted Monday morning, after the party's candidates were soundly beaten in Sunday's Tokyo Metropolitan Assembly election.

But with the Upper House election less than a month away, party leaders said Hashimoto will stay at his post, with many of Nippon Ishin's rank and file saying a leadership change now would simply further damage its popularity, which has plunged since Hashimoto's May remarks were taken as an attempt to justify Japan's wartime "comfort women" system of sexual slavery.

Hashimoto, who spent Sunday in Okinawa attending the memorial ceremony marking the 68th anniversary of the end of the Battle of Okinawa, said Monday afternoon in Osaka that he had no plans to resign now.