Along with Marie's old school friend, Houko Hoshinomiya, Naoto and the others observe the coup d'etat when they get a report that the Japanese government is going to use the Tall Wand against the Yatsukahagi. As the time draws close to the impact of the Tall Wand, Gennai, the mastermind behind the coup d'etat, fires the Yatsukahagi's main cannon. The two geniuses, Marie and Naoto, face a new challenge in order to stop Gennai's rampage.