Kansas City is about 1.3 times bigger than Tokyo.

Tokyo is approximately 619 sq km, while Kansas City (map shows its 145 named neighbourhoods; the area covers the whole city) is approximately 815 sq km, making Kansas City 32% larger than Tokyo.
Tip: This to-scale comparison of Tokyo vs. Kansas City 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.