The Collapsing Castle

The Collapsing Castle (崩れゆく城郭, Kuzureyuku Jōkaku) is the 48th episode of the Kekkaishi anime adapted by Sunrise.

Summary
"Though Yoshimori didn't realize it, the woman he met was none other than the Princess, the master of Kokuboro. She granted him her powers, which enabled Yoshimori to find and rescue Sen Kagemiya. Tokine, desperately searching the vast citadel for Yoshimori, defeated a Kokuboro executive called Koshu. And meanwhile, in yet another part of the castle, Heisuke Matsudo faced off against his archnemesis Byaku in a fight to the death."

- English dub narration

Kokuboro's castle continues to collapse around Tokine as she races through it, still searching for Yoshimori. She comes across several fleeing Ayakashi, traps three of them in Kekkai, and forces them to tell her where Yoshimori was being held. Sen follows Yoshimori away from the dungeon, amazed that he is able to handle so many Ayakashi so easily. Yoshimori mentions that there are worse ones in a room ahead, but so long as go through quietly, there shouldn't be any trouble. Suddenly, an enormous amount of Ayakashi bugs rush toward them, startling the pair. Tokine hears their shouts, and her prisoners beg her to spare them. She agrees if they will cooperate with her, so they tell her how to reach the dungeon where Sen was being held. Tokine frees them and heads for the dungeon.

Yoshimori protects himself and Sen with a Kekkai, but the Ayakashi ignore them and focus only on escaping. Sen is unable to remain calm around so many bugs, so Yoshimori raises his Kekkai to the next floor. Yoshimori teases Sen about being afraid of bugs, and Sen angrily asks why Yoshimori saved him if he is such a burden. Yoshimori says it's normal to save a friend, but this only irritates Sen, as it reminds him that Gen Shishio would save him without being asked as well. Yoshimori replies that he doesn't mind himself getting hurt, but that he can't allow others to be hurt around him. After they reach the outer part of the castle, Yoshimori tells Sen to follow the fleeing Ayakashi bugs and escape. Sen refuses, not wanting to get close to them, but Yoshimori makes a path through the air with his Kekkai, leaving Sen unable to follow him.

Masamori's search party finally locates Tokiko, who has completed the portal to Kurosusuki. She allows them to use it, but warns that the dimension has started to collapse, and anyone trapped inside when it collapses will vanish with it. Masamori informs her that Yoshimori, Tokine, and Sen are inside, and selects a small group of his people to go in with him. Mukade, Hakudo, Odo, Hakota, and Yukimasa are chosen, and Shigemori insists on going as well. Tokiko chooses to remain behind so she can maintain the portal. Mukade brings out a large shadow bug for the group to ride on, and they enter the portal.

Tokine reaches the dungeon, but only finds the webbing that once held Sen. Sen manages to follow Yoshimori with some difficulty, and offers to find Kaguro for him. Sen explains that he can track powerful Ayakashi by their auras, but doing so leaves him vulnerable, so he asks Yoshimori to protect him. Sen flares his own aura, and detects several powerful Ayakashi. As Yoshimori begins to describe Kaguro, he suddenly remembers that Kaguro was wearing a human skin disguise, and assumes Sen won't be able to find him. Sen gets angry because he thought he would finally be able to help. Yoshimori apologizes and tells Sen to go home, and heads out to find Kaguro alone. Soon after, Tokine runs into Sen (literally), and he offers to track Yoshimori for her. Just as they find him, however, the building collapses around them. Sen manages to grab a broken post, but Tokine falls into a dark pit.