In the normal world the sky is blue and the grass is green. The color of natural hair ranges from white to brown to red to blonde to black. Eyes are usually green and blue or hazel and brown or black. Though in the mirrored world the sky is red and grass is blue and hair is green and pink and blue while eyes are an unatural color. Also in this world there are monsters with a knack to do evil in the normal world. You are an Exterminator. You hunt these demons down in both world while trying to maintain a norma teenage life. You travel to the other world through reflective mirror like surfaces and so do the monsters.
So basically your a high school student (will allow a few middle school or college students) trying to maintain a normal life but also killing and exterminating the monsters that do evil. Though not all monsters are evil. You will travel between the two worlds and save the day, over and over again.