Where the millionaires live now

The Tokyo skyline. Expats living in the Japanese capital are paying more rent than anywhere else in the world due to the soaring yen, while those in Hong Kong would have seen theirs rise 22 percent, a survey has revealed.

If you're in Tokyo, look around. Millionaires may be all around you.

That's because the bustling city ranks first when it comes to the place with the most millionaires, according to a new study from WealthInsight, an independent research firm based in London, UK.

Why Tokyo and not London or New York, you might ask?

"It has to do with concentration," Andrew Amoils of WealthInsight told CNBC, who noted the millionaires in New York are spread out over multiple cities.

Tokyo tops the list with 461,000 millionaires, while New York ranks second with 389,000 millionaires. London came in third with 281,000. Millionaires are defined as individuals with $1 million or more in assets.

The ranking is slightly different when it comes to multi-millionaires, or individuals with more than $30 million, with London topping the list, followed by Tokyo and Singapore, FT Alphaville notes.

The United States has the most millionaires, followed by Japan and Germany. However, China may snag the second spot by 2020.