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The Upper Key is one of two keys found in Blowhole Castle in Wario: Master of Disguise, the other being the Lower Key. It is found in a purple treasure chest in the room directly below the dark area where the Lower Key is used. In order to reach the chest, the room must be entered from the right with the spirit switches turned on. The Upper Key unlocks a door with the key's image next to it in the room with the trio of Buffy the Dolphins where the Lower Key is found.