The Another Logic Counter Agency (異世界対策機関 Isekai Taisaku Kikan, lit. Parallel World Countermeasure Agency), or ALCA (アルカ Aruka) for short, is a Septpia-based special police force dedicated to protecting the world from dangerous foreigners, travelers from different worlds who come to Septpia. To do so, they train young logicalists and partner them with allied Foreigners, whom which they can combine with using the Trance ability to give them the power to fight. There are five ALCA branches throughout the nation that the anime takes place in, as well as a branch in Hong Kong.