The term of office for half the members of the House of Councillors serving in the first term under this Constitution shall be three years. Members falling under this category shall be determined in accordance with law.
この憲法による第一期の参議院議員のうち、その半数の者の任期は、これを三年とする。その議員は、法律の定めるところにより、これを定める。
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.