What is the capital of Japan?

The capital of Japan is Tokyo, which has been the country's political and cultural center since the mid-19th century. Originally a small fishing village named Edo, it became an important city when the Tokugawa shogunate moved there in 1603. The name was changed to Tokyo, meaning "Eastern Capital," when Emperor Meiji relocated the imperial capital there from Kyoto in 1868.

Other cities listed in the options represent capitals of different countries in Asia. Beijing is the capital of China, Seoul is the capital of South Korea, and Bangkok is the capital of Thailand. While these cities are also significant in their own right, they are not the capital of Japan, which is why Tokyo is the correct answer in this context.