Translation guide
A very large, heavily populated urban region consisting of multiple cities and suburbs that have grown together.
The speaker wants to refer to a huge, continuous urban area formed by the merging of several cities.
Direct loanword from English, widely understood in Japanese. Used in geography, urban planning, and news contexts.
Literally 'giant metropolitan area'. A more formal, descriptive term often used in academic or official contexts.
Loanword 'megacity'. Often used for a single huge city, but sometimes extended to a megalopolis. Less precise.
The area from Tokyo to Osaka is called Japan's megalopolis.
Over 30 million people live in this megalopolis.
Tokyo is one of the world's largest megacities.