AR-Field

The AR-Fields (ARフィールド) are spaces between the and the Human World created by Leviathan. They resemble a ruined version of the Human World, as they are simulations of the world Leviathan will create if it manages to take over it. The AR-Fields are the only place where Appmon can materialize without appliarising. Only an Appli Driver can enter an AR-Field using their Appli Drive.

Cyber Arena
The Cyber Arena (サイバーアリーナ) is a place where Appmon compete. is the referee of the Cyber Arena. The Cyber Arena seems to be able to appear in any AR-Field, as Haru Shinkai, Eri Karan, and Torajirou Asuka can access it from the Fujimizaka Middle School, while the can access it from the Hifumigaoka Middle School.