|} is the upper house of the 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 designation of the prime minister, the House of Representatives can insist on its decision. In all 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 242 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 cannot be dissolved, as only half of its membership is elected at each election. Of the 121 members subject to election each time, 73 are elected from the 47 prefectural districts (by single non-transferable vote ) and 48 are elected from a nationwide list by proportional representation with open lists.
Up to the 1998 election, there were 252 members, 126 elected at a time: 76 from prefectural districts and 50 elected nationwide. At the 2001 elections these numbers were reduced and the total number was 247 (126 elected in 1998 and 121 elected in 2001) and the open list preference vote was introduced.
See List of members of the Diet of Japan for the list of current members of the House of Councillors.