You could say all governments where oligarchies, dictatorships and representative governments until the 18th century

The reason for the rise of the shoguns was that Japan lacked a centralized government and the Japanese emperors

Tried to copy the emperors of Japan when in reality a more feudal based system would have worked better for Japan

The reason why the brief imperial restoration in the 14th century didn't last long because the Japanese emperor didn't accept

Political realities is that Japan is ruled by a warrior class not by civil servants