LDP's own seniority system, which regulates the struggle for power between the party's competing factions, is particularly rigid.

ECONOMIST: Japan

The decision coincides with LDP resistance to efforts to allow a jury system in Japan, says Kohei Nakabo, the former head of the Japan Federation of Bar Associations and now the chair of a committee to reform the legal system.

FORBES: Japan's Dirty Secrets

Third, by overthrowing the LDP, Japan's voters have turfed out not just a party, but a whole system.

ECONOMIST: Japan's election