Before Chise became the "ultimate weapon," there was another—Lieutenant Mizuki. A battle-hardened military woman, she volunteered for an experimental procedure after injuries left her unable to return to the battlefield. As the prototype ultimate weapon, Lieutenant Mizuki was highly successful on the battlefield, however, as the first candidate, her development was limited. When a more suitable candidate to become the weapon, Chise, is forced into the military, Lieutenant Mizuki thinks that she is silly, weak, and unsuited for the role. As the only other person to have undergone the procedure, however, Lieutenant Mizuki can hear Chise's thoughts and is the only one who understands her. As the war rages on and Chise's development progresses, Lieutenant Mizuki discovers more about Chise, ultimate weapons, and herself.

A large scale remake of the time after Kenshin leaves Tokyo up until before the inferno of Kyoto.

Strange suicides have been taking place in New York. One day, four girls from the same high school wake up in the morning feeling tired and dizzy and not being able to remember anything about the previous night. In school, they find out that one of their classmates has committed suicide. School is canceled for the rest of the day, but instead of going home, the girls are drawn to a park by butterflies only they can see. Suddenly a man and a woman approach the girls, telling them that they all died the previous night. (Source: ANN)

A runaway vehicle driven by Izumi Yasaka, en route to the Public Safety Bureau building, is reported shortly before it crashes into the building. Izumi is a counselor who recently ran away while working at a latent criminal isolation and rehabilitation facility known as Sanctuary. Before Inspectors Mika Shimotsuki and Akane Tsunemori get to interrogate the suspect, a sudden request is issued from the facility to promptly bring Izumi back. Interpreted as a direct order from the Chief and the board at Sanctuary, the Inspectors obey, but insist that Izumi be escorted back personally. Tsunemori intends to investigate further with the rest of the team at the Bureau. Now Inspector Shimotsuki has finally been given the opportunity she had been waiting for—to be the primary investigator on an important case. This case follows Shimotsuki and her team of Enforcers as they uncover the secrets of Sanctuary.