In terms of politics and the political system, pre-WWII Japan was officially a democracy. It had an emperor but he did not really have that much power. However, because of flaws in the way that their system was set up, their military was pretty much able to control their government. This happened in part because the people accepted the idea of militarism -- the idea that the military was morally superior to the civilian government. The fact that the military could control the government really helped lead to WWII.
The Japanese economy was dominated by the huge (mostly family-owned) conglomerate businesses. These were called zaibatsu and were generally supportive of the military as well.
Culturally, Japan had been getting to be more and more like the West. However, it was still very traditional compared to the way it is now.
The most overwhelming feature in my mind of Pre World War II Japan was its obedience to the Emperor. Simply put, the Emperor was seen as an individual who could do no wrong. Japanese culture and its civilian population were not accustomed to questioning the strategy or tactics in Manchuria, the human rights violations in the Pacific Rim, or even its alliances with the other Axis powers. It was this blind obedience to the Emperor and the authority structure that compounded the difficulty in grasping the ending of the war with the atomic bombs dropped on Hiroshima and Nagasaki. Naturally, there was confusion and uncertainty given this new form of warfare. Yet, there was additional obscurity in attempting to understand how an authority structure could have been so wrong in leading its people down a path of social and national destruction. Japanese culture of blind obedience to authority in both a civic and institutional point of view seems to me to be a stunning feature of its society before the war.