Iron Princess Mask lead a scheme alongside Temujin's backing to steal ten 100-carat blue diamonds from throughout Tokyo, which she would use for a special "diamond beam cannon" created for the Black Cross to destroy an EAGLE facility researching the power of plasma from the sun; with the explosion, the plasma would be enough to destroy a major section of Tokyo once released. In order to secure success for her mission, she made it seem like the Gorenger were the ones behind the scheme, using multi-colored parasols and capes with a group of Zolders while saying the Gorenger's catchphrase to lure the police into thinking they were behind it and even placing a life-like statue of Peggy in front of a camera to cause further suspicion. The Gorenger try to elude Iron Princess Mask and prevent her from getting her hands on the ten diamonds, but she ultimately does, securing the last from an agent who she receives it from before killing to keep him quiet.
When the Gorenger finally catch up with the Masked Monster, she has completed the Diamond Beam Cannon and prepared to fire it at the plasma facility. However while in the midst of the battle with the Gorenger, she is lured away long enough for Momorenger to waste her shot on her; Iron Princess Mask ends up sacrificing her powerful parasol to prevent it from destroying her instantly. The Gorenger finish her off with "Gorenger Storm New Power: Momotaro", sending a peach at her which she slices with her handle sword, revealing the Gorenger Storm ball that hits and destroys her.
Modus and Arsenal
Iron Princess Mask's main weapon is a multi-purpose parasol that can use as a shield, a deflection device, a staff and even holds a sword hidden within its handle. She also has a long tongue to lick up objects and can fire bullets from her nipples.