The Chief Cabinet Secretary (内閣官房長官, naikaku kanbō chōkan ) of Japan is a Minister of State who is responsible for directing the Cabinet Secretariat. The main function of Chief Cabinet Secretary is to coordinate the policies of ministries and agencies in the executive branch. The Chief Cabinet Secretary serves as the government's press secretary, conducts policy research, prepares materials to be discussed at cabinet meetings, and, in time of national crisis, coordinates ministries and agencies of the executive branch. The Chief Cabinet Secretary is customarily nominated as the first in line to serve as the Temporal Acting Prime Minister in case the Prime Minister is unable to serve due to death or other grave reasons until a new Prime Minister is appointed. The Chief Cabinet Secretary's office is located on the fifth floor of the prime minister's official residence in Tokyo.
Before and during World War II, the position was known in Japanese as 内閣書記官長 (naikaku shokikan chō). The modern position was created on May 3, 1947, shortly after the passage of the Constitution of Japan, and elevated to ministerial status in 1966. Yasuo Fukuda, who served under Yoshirō Mori and Junichiro Koizumi, is the longest-serving Chief Cabinet Secretary in history, having spent over 1,289 days in office.
Since 1947, the office of Chief Cabinet Secretary has been regarded as a stepping stone to the post of prime minister. The first Chief Cabinet Secretary to become prime minister was Ichirō Hatoyama, formerly Chief Cabinet Secretary to Tanaka Giichi. Since then, eight other Chief Cabinet Secretaries have become prime ministers, most recently Shinzō Abe and Yasuo Fukuda.内閣