Hiroshi Moriyama, the secretary-general of the ruling Liberal Democratic Party, has such a powerful influence over the administration of newly elected Prime Minister Shigeru Ishiba that a former Cabinet minister within the party has labeled it a "de facto Moriyama Cabinet."

Moriyama has served as the LDP's parliamentary affairs chief for roughly four years and two months — the longest anyone has served in this position — and has experience in other key party roles such as election strategy chief and chair of the party's decision-making General Council.

He exerted his influence as soon as Ishiba, whose power base within the party is fragile, informally decided to name him as party secretary-general. He advised Ishiba to dissolve the House of Representatives shortly after being named the country's new prime minister so that a snap election can be held on Oct. 27.