Kagami lived in a Phantom Field alongside Ciel Sulfur. One day, their Observer was released from the torment of monitoring the Field, but instead of their world being corrected and reformed into a future Possibility, it vanished. Before this happened, Kagami took Ciel aboard the Dimensional Boundary Submersible Warship Fugaku, a submarine that can withstand the Boundary. At some point, Kagami's personality was put into Raabe, an Independent Thought Unit. Kagami would send both Ciel and Raabe into different Phantom Fields to not just free the trapped Observer, but to also glimpse some clues on how to save their lost world.
Ciel and Raabe returned from a Phantom Field which was Observed by Trinity Glassfille. With them was Rei, a young person with a Drive that allows them to perform extraordinary levels of Observation. Kagami clarified everything she could to them, explaining Phantom Fields and the state of the one that Rei, Ciel, and Raabe had just returned from. Although Kagami was watching everything unfold within the Field from the safety of the Fugaku, she was unable to intervene in anything, and would have liked the retrieval of Another Dark Mai. Regardless, Kagami asked Rei to join their cause and named their Drive as End Gazer. Rei accepted. The following day, Kagami guided the group to Dive again into another Phantom Field. When they came back from the Phantom Field, one created by Bullet, Kagami congratulated the group on another successful mission.
- BlazBlue Alternative: Dark War, Chapter 1, 1 - 1.
- BlazBlue Alternative: Dark War, Chapter 1, 12 - 6.