The National Diet, the Japanese chamber that cannot be dissolved, and its six-year terms

Background

With the 222nd session of the Diet sitting and the consumption tax bills before it, the shape of Japan's legislature is worth setting out.
The National Diet is described as the highest organ of state power and the only law-making organ of the State.
It has two houses, and the upper house is the House of Councillors, called the Sangiin in Japanese.
That house deliberates bills, budgets and treaties, investigates national questions and takes part in exchanges with parliaments abroad.
Unlike the lower house it cannot be dissolved, and its members hold six-year terms.
Being free of dissolution is what lets it take the long view on policy, by its own account.
It describes its mission as that of a chamber of wisdom and a chamber of reconsideration.
Its presiding officer carries the title of President of the House of Councillors.