The basic platform of Tokyo Gov. Yuriko Koike's new Kibo no To (Party of Hope), with promises of freezing the scheduled income tax hike to reducing the salaries and number of Diet members, has a familiar ring for many members of the Osaka-centered Nippon Ishin no Kai, which has agreed to cooperate with Koike in the coming election.

"Kibo no To's policies and political philosophy are basically the same as Nippon Ishin's," Nippon Ishin co-leader and Upper House member Toranosuke Katayama said in a recent speech in Nagoya. "The kind of reforms it is talking about are things Nippon Ishin has long pursued."

Both parties are considered to be conservative to right wing, and both favor neoliberal economic policies and smaller government. However, while they have many policy similarities, a genuine merger is problematic. Both parties want to remain similar but have different priorities, with Nippon Ishin pressing a more detailed decentralization plan and Kibo no To offering only general promises.