It has been seven months since the transfer of the Dark Irregular into Kanna as well as the loss of her memories of her dear friend, Kenneth. Life has been normal for the young apprentice of Division Thirteen, but throughout the endless days of tedious and disciplined training, studying, and spending the occasional day with her friends, Kanna has been feeling empty despite being filled with the presence of her new irregular.

After seven months of the same daily routine, a family from the minor kingdom of Rohnay arrives to have a meeting with the queen and inform her of the eight Dense Shadows that have been raiding towns and cities on the border between the east and west sides of Sylenia. These same, alarmingly human-like, Dense Shadows suddenly strike the Palace of the Crimson rose during the new knighting ceremony. Kanna finds one of them oddly familiar.

As one of the apprentices chosen to seek and eliminate the eight Dense Shadows, Kanna is eager to figure out the reason behind their raids as well as why that one shadow seemed familiar. To her horror, the raids and shadow are the least of her worries, for there is a high possibility that one of the dark queens is trying to breach the wall that keeps the two parallel worlds apart.

And she is not afraid to use any means necessary to do so.