Final answer:
The capital city of Japan, home to cities like Hiroshima, Kyoto, and Nagasaki, is Tokyo. Tokyo is the world's largest metropolitan urban area and has great historical and cultural significance.
Step-by-step explanation:
The capital city of Japan, which has cities like Hiroshima, Kyoto, and Nagasaki, is Tokyo. Tokyo, formerly known as Edo, is not only the political capital but also the largest metropolitan urban area in the world. The cities of Hiroshima and Nagasaki are historically significant for being the targets of atomic bombings during World War II, while Kyoto was the capital of Japan until 1868 and is renowned for its historic sites and rich cultural heritage.