Amakudari ("descended from heaven") is a Japenese word describing the reemployment of government bureaucrats after the termination of their service with the government. This is an important part of Japanese economy, and the practice is well integrated into the framework of the Japanese employment system. In Japan, they consider amakudari as an extension of the mutual commitment of employer and worker within the tradition of lifetime employment.
The Japanes tradition, that whenever a government official is promoted to the highest position (Vice-minister), all those of same age or older resigns, I think, makes this a necessity too.
And it seems, such a system fosters strong links between business and the state, which is also a top reason for the commendable performance of Japanese industry.