Musashi Province was a province of Japan, which today comprises Tokyo Metropolis, most of Saitama Prefecture and part of Kanagawa Prefecture. It was sometimes called Bushū (武州). The province encompassed Kawasaki and Yokohama. Musashi bordered on Kai, Kōzuke, Sagami, Shimōsa, and Shimotsuke Provinces.

Tokyo, officially the Tokyo Metropolis, is the capital city of Japan and one of the most populous cities in the world, with a population of over 14 million residents as of 2023. The Greater Tokyo Area, which includes Tokyo and parts of six neighbouring prefectures, is the most-populous metropolitan area in the world, with 40.8 million residents as of 2023.