Their are a lot of similarities between the cultures of Japan and China, but they both quite distinct with their own history, background, and traditions.
Also note that Japan has adopted a very 'Americanized' way of life in the last 50 years. Tokyo is similar to NYC and they have more gadgets and high tech gizmos than most Americans do. They also have a westernized government.
China only embraces Western culture if it means profit for the country. Everyone knows that China is communistic and anyone that shows dissent is punished. For example: Tienamen Squre.