Key the Metal Idol, 1 layer, no sketch, A15, original non-matching background, OVA
Periodically in the anime Key the Metal Idol, Key will change into Tokiko, a human girl. Her coloring changes and she often shows emotions. Sometimes this is of very short duration, but sometimes she stays this way for a while. There are hints as to why this happens throughout the OVA, but it is fully explained in episode 14: System.
Vapalla's Cels 