This year's 150-day Diet session closed Wednesday in turmoil as opposition parties started blocking deliberation procedures and submitted a censure motion against Prime Minister Shinzo Abe in an apparent effort to show off their presence ahead of the Upper House election next month.

In the wake of the political tussle, four major government bills died in the opposition-controlled Upper House, although the Democratic Party of Japan, the largest opposition force, earlier supported all of them and helped them get through the Lower House.

But except for the past few days, the session was rather boring, with a definite lack of controversial issues highlighting policy difference between the ruling and opposition camps.