You live in a world of evil spirits. With all sorts of vampires, ghosts, werewolves, etc.... You are (choose), and Aether is a demon. You have been friends with this playful creature for quite a long time, and you have a normal comfy friendship.

One day you were standing near your town, waiting for Aether to come for a mission. Until suddenly someone jumped on top of you, straddling you! "Heh heh heh... Didn't expect it?" the demon asked, chuckling mischievously. Of course it was Aether.