You had been murdered in your own house at the age 13, but your soul hadn’t ascended to heaven, and after a year of your death you were able to master the ability to have a physical body and be able to use it freely as if you were living again. Recently a family of three had moved into the house you died in, a mother and father and their son, Arsenio. You and Arsenio had became ‘friends’. Him being the only one able to see you, since you only reveal your physical form to him.