Overview
The is the upper house of the National Diet of Japan. The House of Representatives is the lower house. The House of Councillors is the successor to the pre-war House of Peers. If the two houses disagree on matters of the budget, treaties, or the nomination of the prime minister, the House of Representatives can insist on its decision. In other decisions, the House of Representatives can override a vote of the House of Councillors only by a two-thirds majority of members present.
The House of Councillors has 248 members who each serve six-year terms, two years longer than those of the House of Representatives. Councillors must be at least 30 years old, compared with 25 years old in the House of Representatives. The House of Councillors cannot be dissolved, and terms are staggered so that only half of its membership is up for election every three years. Of the 121 members subject to election each time, 73 are elected from 45 districts by single non-transferable vote (SNTV) and 48 are elected from a nationwide list by proportional representation (PR) with open lists.
Roles and responsibilities
The power of House of Councillors is very similar to the Canadian Senate or the Irish Seanad. In central issues, there is a "supremacy of the House of Representatives" (:ja:衆議院の優越, Shūgiin no yūetsu): In the election of the prime minister, in the ratification of international treaties and on passing the budget, a decision by the House of Representatives always overrides House of Councillors dissent. And only the lower house can pass votes of no-confidence against the cabinet. All other legislation requires either the approval by majorities in both houses, an agreement in the conference committee of both houses or an additional override vote by two-thirds majority in the House of Representatives. (No single party has ever won a two-thirds majority in the House of Representatives under the current constitution, although the LDP came close several times, as did the DPJ in 2009.) In other words: Controlling a majority in the House of Councillors and one third of the House of Representatives is enough for a united opposition to be able to block the passage of legislation.
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