Godzilla suddenly makes landfall from Tokyo Bay. The Self-Defense Forces begin their attack in Kabukicho, Shinjuku. However, during the battle, it is discovered that Godzilla’s body temperature is rising rapidly…!

In Genroku-era Japan, after Lord Asano is forced to commit suicide for attacking Kira, Chief Retainer Araki sends Kaizuka Shingo undercover to investigate Oishi Kuranosuke's motives. As Kiras son deploys spies to stop Oishis revenge, Kaizuka joins the samurai's cause, setting the stage for a historic raid.