Japan's population is over 126 million. Most Japanese reside in densely populated urban areas. Japan's capital city is Tokyo. The population of the Tokyo Metropolitan Area including the city, some of its suburbs and the surrounding area is approximately 12 million.
Historically, the population of Japan has undergone repeated periods of increase and decrease. During the period from approximately 400 years ago to 300 years ago, it increased significantly due to the societal change from the Warring State Period to a peaceful period. Afterward, it remained stable until approximately 150 years ago. Due to the advancement of medical care, changes in lifestyle, and industrial growth, the population of approximately 33,300,000 rapidly increased to the current 127 million. It is, however, estimated to take a significant downward turn in the future due to its aging population combined with its declining birth rate.