Investigator Axel Webb is hired by a Japanese Naichō Agent on the recommendation of his Yakuza friend, Hibiki Sato, to find the Honjō Masamune katana that was last seen in 1945 when it was taken from a Mejiro Police Station by a US Army sergeant. The sergeant’s name was recorded by the police in Japanese. Years later, it is translated back into English. Unfortunately, there is no record of anybody by that name serving in Japan during the post-war occupation. The katana is not just any sword; it is considered the most perfect sword ever made. It is also a symbol of the Tokugawa shogunate. The Japanese government does not want the lost national treasure and ancient cultural symbol to fall into the hands of a newly formed neo-fascist political party determined to gain power and return the country to its pre-war policies.

The new political party, the Meiyo Aru Dōmei, is an alliance of 14 of the most extreme right-wing groups, including politician Junichi Kato, leader of the Azuna-tō, Yakuza, Fukashi Nakamura, Kumichō of the Meiyo-kai, and Daizō Hokama, leader of the alliance, the Meiyo Aru Dōmei. Hokama wants to use the lost Honjō Masamune katana as a rallying symbol that his followers and the public can get behind.

A Toronto podcaster becomes interested in the lost sword. During his research, he works out the correct name of the sergeant who picked up the sword from the police station. He announces he’ll reveal the soldier’s name in his next podcast, but he is murdered before getting the chance. The podcaster’s daughter hires Axel to find out who killed her father. Axel and one of Hibiki’s closest associates, a sumo-sized Yakuza known as Ōotoko, track the sword to a Buffalo gangster, Jimmy Kowalski. But the sword is stolen from him by Nakamura’s men before Axel and Ōotoko can negotiate a deal.

Axel and Ōotoko must deny the extremists their symbol and return it to the government, but the Naichō aren’t the only ones who want the sword. Buffalo gangster Jimmy Kowalski wants his sword back, no matter the cost. And Daizō Hokama will do anything, including murder, to keep it.