The year is 1931, the 64th year of the Meiji era. The 15th Shogun, Yoshinobu Tokugawa, continues to wield absolute power thanks to complete monopolization of a special natural resource known as "Ryumyaku." Supporting the Tokugawa regime from the shadows are the deadly agents of the covert organization known as Nue.

With confidential Nue files having been leaked to their enemies at Kuchinawa, a search is underway for the traitor who provided the information.

Asahi and Yukimura struggle with the nature of their relationship, while the mole leaking Nue secrets is found... or is he?

Jin Kuzuhara is the ruthless, enigmatic head of the shogun's personal group of assassins, Nue. But how did he come to serve the Tokugawa regime? And what is his secret connection to Sawa?