Act for Establishment of the Cabinet Office
Official legal name of the Japanese law that established the Cabinet Office (内閣府). Used in legal and governmental contexts.
The Cabinet Office was established based on the Act for Establishment of the Cabinet Office.
内閣府 is the Cabinet Office itself, while 内閣府設置法 is the law that established it.
Compound of 内閣府 (Cabinet Office) + 設置 (establishment) + 法 (law). The exact historical derivation is straightforward from the components.