Ōke

All but two (the Kan'in-no-miya and Nashimoto-no-miya) of these ōke (王家 "Royal Houses") were formed by the descendants of Prince Fushimi Kuniie.

At that point, no male heir had been born to the Imperial family in 40 years, prompting concerns that there wouldn't be anyone to succeed Crown Prince Naruhito after he became emperor.

[3] Media opinion polls showed an overwhelming majority favoring the change, but the proposed revision was met with fierce opposition from conservatives, who held that the imperial dynasty, which had survived in an unbroken line stretching for nearly 2700 years, could not be dismissed and ended by a wave of deracinated modernity and uncaring recentism.

Although Takeda has written that such men should feel a responsibility to maintain the royal house, he said he would find it daunting if asked to play that role himself.

[5] Opponents of the reinstatement of former collateral branches, like Liberal Democratic Party politician Yōichi Masuzoe, argued that it would favor members of families with tenuous blood links to long-ago emperors over contemporary female descendants of recent sovereigns.

[7] Another proposal was to reinstate four of the former imperial families,[8] a solution opposed by the government on the grounds that it would not enjoy public support.

[9] Government sources told the Yomiuri Shimbun in May 2012 that the suggestion to reinstate men from the former princely houses as imperial family members through adoption had been unexpected.