This is a broad ranging topic that requires an exhaustive account of history and sociology. Since I live in Japan I will give you just a few points to explore based on my experience living and working here in Japan. How has Japan changed since ancient times to the present has a lot to do with the national identity and character associated with Japanese culture.
In Ancient Japan, the Japanese were an agrarian people. They toiled in their fields and farmlands yielding crops, vegetable, and fruit that they would either sell on the market, trade with others, or give to marauding samurai. In terms of wealth the Japanese were poor, but they shared what they had. They were generous and thoughtful.
There was a strong sense of community amongst the Japanese people and a strong devotion to the hierarchy. That means following socially acceptable norms of the times, and not questioning this hierarchy nor the government. You did what you were told.
Strong community cohesiveness was very important for the Japanese back then, even during the most difficult of times. Giving was more important than receiving. Trust was not earned, it was given regardless of who you were. Your word was your bond.
Virtues such as patience, kindness, mercy, and devotion to the martial spirit were common place. Letters and the arts flourished in ancient Japan and people strove to excel in these areas. There was a sense of wholesomeness and purity that transcended money and power.
Modern Japan has all but forgotten about the core virtues. Many of them focus only on their jobs and careers while caring very little about other people. Trust no longer exists outside of each person’s closed community, and people no longer greet strangers nor do they open their doors to them. The computer is the new paradigm for socializing. Young people have become more withdrawn from society, no longer able to deal with the pressures of dating, marriage, and career.
Many young working professionals have settled for mediocre positions within their companies because they have no interest in being promoted. Japanese culture has lost a lot of its appeal with the younger generation. Japanese kids are more interested in Christmas and Halloween and celebrations that have nothing to do with their own culture and history. Selfishness has replaced generosity. The ancient ways of Bushido are no longer taught in modern academia, and is considered old and outdated. Where there was trust, now there is fear. Where there was hope, now there is doubt.
What’s left are fragmented pieces of Japan’s culture. You can still see the culture in its cuisine, but little by little you see more fusion concepts being adapted into Japanese cooking. National sports such as Sumo, Judo, and Kendo are no longer considered sacred and pure, now these sports are tainted in scandal over criminal allegations of misconduct.