Tokyo is about 1.3 times smaller than Kansas City.

Kansas City (map shows its 145 named neighbourhoods; the area covers the whole city) is approximately 815 sq km, while Tokyo is approximately 619 sq km, making Tokyo 75.99% the size of Kansas City.
Tip: This to-scale comparison of Kansas City vs. Tokyo uses the Mercator projection, which distorts the size of regions near the poles.
Our free app, MapSize by MyLifeElsewhere — compare any two places, to scale on your mobile device.