The Upper Key is a key item that appears in Wario: Master of Disguise.
The Upper Key is a cyan-colored key with the shape of a ghost on the end of it.
The Upper Key is one of two main keys that can be found in Blowhole Castle along with the Lower Key. As the name states, the Upper Key can be used on a door in the upper area with an image of it next to it. The Upper Key can be found in a purple treasure chest in the room directly below the dark room where the Lower Key is found.