Changes in Japanese culture since the 1940s? ?

Question:

Could you help me list some ways Japanese culture has changed since the 1940s? How it was then, and what it is now.

Answer:

You'd better divide it at 1945 (at the end of WWII), instead of 1940's.
After the war, a large amount of western culture, American music and movies in particular, rushed in. Japanese sub-culture scene changed drastically.
Today, Japan is the 2nd largest market of American movies and pop music next to the US.