Records of heads of state
Officially, the current Emperor of Japan, Akihito is the 125th in line from the first emperor Jimmu, who is variously believed to have reigned in the 1st or 7th century BC. The earliest documentary evidence is only for the 29th emperor, Kinmei (AD 509–571); however, this is sufficient such that even the most conservative of estimates still places the Japanese imperial family as among the oldest lines in the world today.
Cabinet of Japan
In practice, much of the Cabinet's authority is exercised by the Prime Minister. Under the Constitution, the Prime Minister exercises "control and supervision" over the executive branch, and no law or Cabinet order can take effect without the Prime Minister's countersignature (and the Emperor's promulgation). While Cabinet Ministers in most other parliamentary democracies theoretically have some freedom of action (within the limits of cabinet collective responsibility), the Japanese Cabinet is effectively an extension of the Prime Minister's authority.
The members of the current cabinet of Japan headed by the Liberal Democratic Party lawmaker Shinzō Abe as of 2 October 2018 are as follows: