Under Article 52 of the Japanese Constitution, a regular session of the Diet is convened once a year with a term of 150 days. Legally, this is called an ordinary session. The term can be extended only once.
There are two other sessions: special and extraordinary.
A special session is convened just after the House of Representatives general election. An extraordinary session is called through a Cabinet decision or a demand made by a quarter or more of all members of either the House of Representatives or the House of Councilors.
At the beginning of each session, the prime minister delivers a policy speech before both Houses