There are 47 prefectures grouped under eight regions in Japan. Kanto region is in green and Kansai region (where Oda is from and where Koshien is held) is in dark blue.
The Kanto region has seven prefectures: Gunma, Saitama, Tokyo, Tochigi, Ibaraki, Chiba, and Kanagawa.
Saitama Prefecture is a prefecture of Japan located on the island of Honshū. The capital is the city of Saitama. This prefecture is part of the Greater Tokyo Area, and most of Saitama's cities can be described as suburbs of Tokyo (to its south), to which floods of residents commute each day. This is where Nishiura is and is the focus of the summer prefecture tournament.
Gunma Prefecture is a prefecture of Japan located in the northwest corner of the Kantō region on Honshū island. Its capital is Maebashi. It is one of only eight landlocked prefectures in Japan. Except for the central and southeast areas, where most of the population is concentrated, it is mostly mountainous. This is where Mihoshi is. Saitama lies to the south.
Hyōgo Prefecture is located in the Kinki region on Honshū island. The capital is Kobe. This is where Koshien is held.