Before the Japanese cabinet approves a government bill, the bill is first approved inside the governing Liberal Democratic Party. This is the jizen shinsa-sei, the prior review system.
The usual view dates it to a letter of 1962 from Akagi Munenori, chairman of the party’s General Council, to Chief Cabinet Secretary Ōhira Masayoshi. One study argues that it began in 1955, when the party was founded and approval by its Policy Research Council became a condition for a cabinet decision on a bill.