The Imaginary Number District–Five Elements Institution (虚数学区・五行機関(きょすうがっく・ごぎょうきかん) Kyosū Gakku.Gogyō Kikan?), also known as the City of Shimmers (陽炎の街 Kagerō no Machi?), is the mysterious realm that exists in the same location as Academy City, formed through the millions of AIM diffusion fields of the espers that reside in the city.