House of Councillors
参議院
The upper of the Diet's two chambers (Article 42). Its members serve six years, half of them elected every three years, and it is never dissolved (Article 46) — so it always has sitting members, where the House of Representatives can have none. That is not the same as always being open: when the House of Representatives is dissolved the House of Councillors is closed at the same time, and during that closure it sits only if the Cabinet calls it into emergency session because the country needs one (Article 54, paragraph (2)).
Written by AI using Constitution, Arts. 42, 46, 54 and Wikipedia: House of Councillors (Japan) as a reference.