Mikado City

Mikado City ( Mikado-shi) is the main location in the World Trigger Universe. It currently has 280,000 inhabitants and is where Border Headquarters is located.

History
About four and a half years before the start of the series a gate to another world opened and Neighbors appeared in the city and started attacking. A mysterious group named Border appeared and repelled the neighbors. In 2 days East Mikado was destroyed, over 1200 people died, and more than 400 people are still missing. Afterward, Border built their base in the city to protect it from Neighbors.

Forbidden Zone
The Forbidden Zone (also known as Danger Zone) is a large zone around Border HQ that is restricted from the public. Neighbor gates are attracted to this region with Border's technology, making the rest of the city safer. The area, before becoming a designated zone, was largely destroyed and abandoned after the initial large-scale Neighbor attack.