The country with the most populous city in the world is Japan, with Tokyo being its capital. Tokyo is part of the Kanto region and is known for its vibrant culture, advanced technology, and rich history. It boasts a population of over 37 million people in its metropolitan area, making it a bustling hub of activity. The city is a major center for finance, technology, and international business, alongside being a cultural epicenter with numerous attractions such as temples, museums, and fashion districts. Tokyo's efficient public transportation system allows millions to navigate the city with ease.