Osaka Mayor and Nippon Ishin no Kai (Japan Restoration Party) founder Toru Hashimoto will be appointed coleader of the party in a move designed to heal the rift between the Osaka faction and Shintaro Ishihara that is threatening the party's prospects in this summer's Upper House election.

Osaka Gov. and Nippon Ishin Secretary General Ichiro Matsui made the announcement Wednesday in Osaka, saying party leaders will formally endorse Ishihara and Hashimoto as coleaders Saturday.

"By moving Hashimoto (to coleader), Ishihara's burden can be reduced. There are lots of television programs a party leader needs to appear on in the run-up to the Upper House election, and we were worried about Ishihara's physical condition," Matsui said.