The rules of the game are changing in Tokyo's Nagata-cho, the longtime epicenter of Japanese politics.
The ruling Liberal Democratic Party's presidential election campaign, which will almost certainly decide the next prime minister, has revealed how drastically the LDP's power structure has changed in recent times, observers said.
LDP presidential elections were once deadly power struggles between the political heavyweights who headed powerful intraparty factions, backed by dozens of their loyal followers, all built upon a strict seniority system.