the whole Kanto region; all over Kanto
Refers to the entire Kanto area, often used in news, weather reports, or business contexts to indicate coverage across Tokyo and surrounding prefectures.
A heavy snow warning has been issued for the entire Kanto region.
This chain store has outlets all over the Kanto region.
Compound of 関東 (Kanto) and 一円 (whole area, entire region).