Kanto (関東) Region is a region around Tokyo.
Prefectures: Tokyo, Kanagawa, Saitama, Chiba, Ibaraki, Tochigi and Gunma.
It is the most populated region of Japan because of Tokyo. One third of Japanese lives in Kanto. Kanto is a huge plain field surrounded by mountains, and on the mountain side, there are many beautiful nature and Onsen.

Chubu (中部) Region is the center of Japan.
Prefectures: Niigata, Toyama, Ishikawa, Fukui, Yamanashi, Nagano, Gifu, Shizuoka, and Aichi.
Prefectures facing to the Sea of Japan is also called Hokuriku, and to the pacific ocean side is called Tokai. Nagoya is the biggest city in Chubu and Mt. Fuji is located in this region. There are many high mountains with beautiful nature, especially Japanese Alpine.

Kinki (近畿) Region, or Kansai (関西), is in middle west of Japan.
Prefectures: Osaka, Kyoto, Shiga, Mie, Hyogo, Nara, and Wakayama.
Kyoto is the main feature of this region, and there are many historic sites in this region because this area was the center of Japan until the Edo Period. Osaka and Kobe is the biggest cities in this area. Also, many cultures are born or related in this area.

Tohoku (東北) Region, or Oou(奥羽), is northern side of Honshu.
Prefectures: Aomori, Iwate, Miyagi, Akita, Yamagata, and Fukushima.
Tohoku has the great nature spots because most of the areas are mountains, especially Shirakami Mountains are UNESCO World Heritage Site. Lots of waterfalls and beautiful forests are in Tohoku. Sendai is the biggest city in Tohoku Region.