In the Shigetomi department store circa 1930, Goemon slashes wildly at Lupin who manages to escape while remarking that his sword is not Zantetsuken. Colonel Daidoji and Major Hongo arrive and snatch the key to the automaton clock from Sarantuya, who is also later revealed to be the heir to the Altan Khoto Kingdom. Daidoji's plan is for the Imperial Japanese Army to instill a puppet government in Inner Mongolia. Following a series of intersecting events, the key players in the drama, Ruriko, Sarantuya, Akechi, Black Lizard, and Lupin, find themselves surrounded by high mirror-like panels with a type of control panel in the center...