Kokutai, a word with many associations in Japanese politics, is often rendered into English as national polity. "Among nationalists of the late 19th and early 20th cents., a term referring to the Shinto-Confucian idealization of the Japanese nation-state. Japanese society was compared to a large family, with the emperor at the head as the benevolent guiding hand and patriarch." 
Strengthening kokutai was the focus of the Imperial Way faction in the 1930s, a right-wing political-military group of the 1930s, which emphasized spirituality and cohesion over the modernization and economic reforms of the Control faction. Sadao Araki was the central leader of Imperial Way. Lower-level officers conducted assassinations, such as that of Tetsuzan Nagata, and unauthorized military actions, such as the Manchurian Incident, under the principle of insubordination (gekokoju) in the cause of kokutai; they sometimes received only mild punishment.
Preservation of the national polity, interpreted as the continuation of the Emperor, was one of the key issues in the surrender terms of Japan; it was essentially the only condition.
- John Bowker. "Kokutai." The Concise Oxford Dictionary of World Religions. 1997. Encyclopedia.com. (July 8, 2010). http://www.encyclopedia.com/doc/1O101-Kokutai.html