Although I would say that Japan is much more homogenized after our post-WWII reconstruction. I think most current Japanese citizens are atheistic, materialistic and revere the state as an all-encompassing entity. Not really nationalism in the traditional sense, but rather the global one.
It is easy to mistake the Japs as worshippers of the State and conformist. Quite the contrary, the State often dissapoints them and they let the State know. The Japs loyalty is first and foremost to "family" and familial networks in general.
They are 180 million people crammed into a small space where %80 of the land is mountainous national park.
Co-operation is essential.
As for being materialists? Well, the people are actually poor while the State is rich. They can afford the odd mod-con as they usually build them. There living spaces are SO small they cannot cram there apartments with "widgets"...although I sense you meant "materialist" in the pure spiritualist sense...i have to disagree...they are Shinto Buddhists who worship the Sun. They are "asthetic" as opposed to "atheistic" and even though the signs of social breakdown are gathering there societal cohesion will hold against the "current" shaking up of the Geo-Political structure.
China in large part is being "fattened" on Western Capital to counter the growing desire of Japanese Elites for a more expansive foreign policy. Japan is a SLEEPING GIANT in terms of the ability to wage a high tech war. If the Japanese desired to challenge U.S hegemony they could do it easily...however...they are hamstrung by ONE giant factor - access to resources. They have the MIGHTIEST industrial capacity of ANY nation in the world. They have the most integrated economic system with a cohesive workforce ANYWHERE in the world. They do not require MASSIVE government subsidy (Pentagon) for their high tech. If they want to build a faster Playstation they just go out and do it. They do not "manufacture" enemies and then demand the taxpayer spend 200 billion manufacturing a Fighter Jet that gives a few spin offs to the private sector.
In closing...I admire the Japanese...they have in part balanced the individual need to the larger "good". It's not perfect. They also have ingrained in their culture a FAR greater respect for freedom of speech and ideas than ANY other country I know. They are willing to listen to criticism when couched in respectful terms...for instance...an American English teacher married a Japanese woman and decided to live permenantly in Japan. He was highly critical of Japanese culture and was VERY vocal about it...when he went for citizenship he stated he would not be holding back on his point of view. He was told..."thats fine".
I wonder how a Japanese University Professor would go criticising the U.S vocally and stating on his citizenship papers that he would be giving the State hell about it's policies?