In Volume 11 of Kekkaishi, the various kekkaishi from the Night Troops lament the death of their member, Gen. Our hero, Yoshimori, vows to avenge his death by destroying the ayakashi group, The Kokuboro, responsible for the murder. In the middle of intense training, the Night Troops drop in on Yoshimori. One night, the Kokuboro mount a huge attack of the Karasumori site, and the Night Troops desperately try to defend themselves.