Osaka Ishin no Kai won two of the Osaka district's four seats and another in neighboring Hyogo Prefecture, as well as at least two proportional seats, inching Prime Minister Shinzo Abe closer to the two-thirds majority needed for a referendum on constitutional revision.
The party failed, however, to generate much interest outside the Osaka region.
"Over the course of the campaign, I've traveled from Hokkaido to Okinawa, and have found there's a lot of sympathy for the kinds of structural reforms we've achieved in Osaka," Osaka Ishin Secretary-General Nobuyuki Baba told a post-election briefing.