TOKYO— Acting Prime Minister Mikio Aoki rose to power in much the same way his boss did: by quietly working up the ranks in Japan's faction-based political system.
Aoki, who took temporary control of the government Monday, was largely unknown in Japan until Prime Minister Keizo Obuchi appointed him chief Cabinet secretary last October.
Even in the aftermath of Obuchi's hospitalization, few expect Aoki to have much influence on policy. He is largely seen as a caretaker to keep the government operating through the crisis.
Nor is Aoki seen as a serious successor should Obuchi be unable to return to work.
Yet he has been no stranger to political power.
Aoki, 65, comes from the same part of Japan — Shimane Prefecture — as Liberal Democratic Party power broker Noburu Takeshita, and started working as Takeshita's personal secretary in 1958.
Takeshita eventually became the leader of the largest faction in the ruling LDP and served as prime minister in the late 1980s. Despite recent illness, Takeshita is still considered influential.
Obuchi inherited leadership of Takeshita's faction, and when the prime minister needed someone to lead his Cabinet last year, Aoki got the call.
"He has seen a lot because he was working for someone at the center of power," said political commentator Minoru Tada. "But I don't think he can make political decisions."
His career in some ways mirrors that of Obuchi. When Obuchi took office in 1998, he was seen as a political unknown whose most famous role had been to announce the name of the reign of Emperor Akihito in 1989.
Despite ties to Takeshita, Aoki did not appear on the national stage until he won a seat in the upper house of Parliament in 1986.
Even after that, he had a low profile, concentrating on fisheries and agricultural affairs, all the while assuming secondary leadership positions with the LDP.