The Liberal Democratic Party won a landslide victory in the July 21 Upper House election and regained control of both chambers of the Diet, ending years in which the legislature was effectively divided and bills were held hostage.

In recent years, whatever force was in power, meaning in control of the Lower House, didn't have a handle on the Upper House, including when the LDP was in the opposition from 2009 to 2012, resulting in stalled legislation and unstable politics, a situation Japanese term "the twisted Diet."

During the LDP's long unchallenged run from the early postwar period to the 1990s, the upper chamber was criticized for being a rubber stamp for whatever the ruling party dictated in the Lower House.