Japan contains Tokyo.
The Bonin Islands , also known as the , are an archipelago of over 30 subtropical and tropical islands , some 1000 km directly south of Tokyo , Japan . The are 23 municipalities that together make up the core and the most populous part of Tokyo , Japan . Tokyo ( [ toːkjoː ] , [ langˈtoʊki.oʊ ] ) , officially Tokyo Metropolis , is the capital of Japan and one of its 47 prefectures . It is the seat of the Emperor of Japan and the Japanese government . Tokyo is in the Kantō region on the southeastern side of the main island Honshu and includes the Izu Islands and Ogasawara Islands .