Differences are:
- In Britain, PM is chosen and appointed by King/Queen; in Japan, PM is chosen by Diet but appointed by Emperor.
- In Britain, Ministers are appointed by King/Queen; in Japan, Ministers are appointed by PM.
- In Britain, PM cannot remove Ministers; in Japan, PM can remove Ministers at will.
- In Britain, all Ministers must be Parliament members; in Japan, only a majority of Ministers must be Diet members.