The First Robot Master fought in my Mega Man 12 Ideas, Party Woman, resides here. Upon defeating her, you would unlock Scuba Man, Inferno Man, and Snow Man's stages, as well as her weapon, Party Bomb. Now, this is the 0.7 Version, so, once the 1.8 update comes out, I'll make a new level.
Party Woman Stage Lore: Mega Man goes to where the Coordinates were, which was a Fun Park where Party Woman used to be the mascot of, (She didn't like it, ironically) and gets through it, finding Party Woman starting a magic show. She fights him, even calling in someone from the audience of robots, as well as her robot cat, Wanda. She's defeated, but, she doesn't explode, instead being knocked back, asking what happened. Party Woman and Mega Man go to Dr. Light's lab, so she can be repaired from any damage caused. Once repaired, she remembers what happened, remembering where 3 of her technical brothers are. (Scuba Man, Inferno Man, and Snow Man)