Easy maps: regions and sight-seeing spots of Japan
Japan is consist of 9 regions (Hokkaido, Tohoku, Kanto, Hokuriku, chubu, Kansai, Chugoku, Shikoku, and Khushu & Okinawa) as you see in this map. It helps you to know the names of the regions during your trip.
Japan has got 47 prefectures stretching from North East to South West, including Capital Tokyo, Osaka, Kyoto and Hokkaido, strictly speaking they are not called “prefecture (Ken)”.
I put Kusatsu and Beppu in the map since the two Onsen places are extremely popular and large as Onsen spots. They are in Gunama and Oita prefecture respectively.