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.

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

Asahi has been kidnapped by Janome, and loyalties are called into question all throughout Nue. Will Yukimura be able to save her adopted sister in time? And will her employers in the Tokugawa government even let her try?

Asahi is alive, but Sawa has seen too much to ignore the crimes perpetrated by Jin Kuzuhara in the name of the Tokugawa regime. Hoping to secure a brighter future for the girl she has adopted as a sister, the assassin once known as Yukimura takes up her sword once again...