Kokuboro's Hostage

Kokuboro's Hostage (黒芒楼の人柱, Kokubōrō no Hitobashira) is the 45th episode of the Kekkaishi anime adapted by Sunrise.

Summary
"The Kokuboro staged yet another attack on Karasumori. Yoshimori, Masamori, and the Night Troops stood firm and fought off the Ayakashi enemy. But now, a fierce battle ensues at Karasumori in the dead of night. Amidst the chaos, Yoshimori sought out the Ayakashi Kaguro, but it turned out to be a trap laid by the Kokuboro. Using a disguise, Shion carried out her orders to capture a young Kekkaishi."

- English dubbed narration

The episode begins with Atora Hanashima still held hostage by Sakon. Miki Hatori asks Masamori for permission to act, but Masamori tells her not to since they can't read Sakon's movements. Atora begs them to ignore her and stop Sakon no matter what. Sakon threatens to kill Atora if they don't surrender Karasumori. Yaichi tries to surround Sakon by sneaking underground, but is easily blown away by Sakon's tornado. Sakon taps into Karasumori's power and begins to transform.

Tokine and her hijacked Ayakashi continue to follow the dark cloud containing the retreating portion of Kokuboro's army. The cloud enters the spirit world through a mountain canyon, and as Tokine passes through, her Ayakashi vanishes from beneath her, and she emerges on the other side, stopping her fall with a Kekkai. She spots the cloud heading toward a large castle, amazed by its size. Suddenly, the air around her shimmers, and Tokine realizes the dimension is in danger of collapsing and hurries to the castle. In the castle, Shion repeatedly tries to overwhelm Yoshimori with her webbing, but he continually repels it effortlessly with a dark aura.

Sakon transforms into a large, armored, humanoid lizard. He threatens to destroy everything if Karasumori isn't surrendered, but Masamori remains unimpressed. Sakon attacks with a tornado, but Masamori dodges it, and uses a Kekkai to slide Atora out of Sakon's grip, followed by a Nenshi thread to yank her to safety. Masamori uses Kekkai as stepping stones to climb high into the air, then forms his Zekkai and plunges straight down at Sakon. Convinced that he is far stronger, Sakon throws multiple tornadoes, but they all prove useless, and Masamori charges through Sakon, destroying a large portion of his head and shoulder. Sakon collapses, and Masamori destroys the rest of his body with a Kekkai. With Sakon defeated, the rest of Kokuboro's army retreats in fear. Masamori assumes that there is still the main portion of the army left (unaware that it has already retreated as well). Shu Akitsu arrives and informs them that he can't find Sen Kagemiya. Shu later spots Sen's jacket where Shion grabbed him. At the Sumimura Home, Madarao returns and tells Shigemori that although Karasumori is safe, Yoshimori has been kidnapped.

Hekian checks on Shion, who is still unable to completely control Yoshimori. She questions whether he is worth all the trouble, but Hekian assures her that a Kekkaishi should be able to repair their dimension. Hekian asks Shion how she was able to capture Yoshimori since she can't touch him. Shion is saved from answering by Byaku's arrival. Yoshimori asks if Byaku is the boss, and when Byaku says no, Yoshimori demands to see Kaguro. As a reminder that Yoshimori is a hostage and that they are in control, Byaku has two Ayakashi bring in Sen and threaten to behead him. Byaku orders Yoshimori to submit to his control worm, reminding him that Sen could die in front of him, just like Gen Shishio did. Yoshimori appears to be ready to submit, but then unleashes a light aura that destroys his bindings and the worm. Shion quickly binds him again, so Yoshimori produces the dark aura again, which appears to destabilize the air around him. Hekian warns Byaku that Yoshimori may damage the castle further at this rate. Byaku orders Shion to keep restraining Yoshimori, and tells Hekian to have Aihi create a device that will extract Yoshimori's power.

Masamori returns home and is shocked to learn that Yoshimori allowed himself to be captured. Masamori calls Hatori at the Yukimura Home and tells her to gather up anyone that is unhurt so that they can head to Kurosusuki. Hekian and Koshu discuss the importance of having Yoshimori submit to them, for the sake of the castle. Koshu explains how the castle used to be far more impressive. He reveals that Byaku expanded the castle rapidly after joining Kokuboro, which is partially to blame for its deterioration.

Shion has her spider goons slowly lower a giant boulder onto Yoshimori's back, though they accidentally drop it on him, and Yoshimori's dark aura reduces the impact. Shion tries reasoning with Yoshimori, but he only cares about finding Kaguro. Suddenly, the roof bursts open, and Kagami flies in with Heisuke Matsudo. Heisuke recognizes Yoshimori at once, though Yoshimori has no idea who he is at first. Shion has her goons attack, but Kagami quickly destroys them. Shion recognizes that Kagami likely comes from another dimension entirely, and decides to escape rather than fight. Heisuke correctly assumes that Kokuboro intended to use Yoshimori to repair the castle. Yoshimori is shocked when he finally realizes who Heisuke is. Heisuke offers to free Yoshimori, but only if he agrees not to attack Byaku, who is his target. Since Yoshimori is only after Kaguro, he agrees and is set free. Heisuke and Kagami set off in search of Byaku, destroying much of the castle along the way.

Differences from Manga

 * In the manga, Tokine doesn't go to Kurosusuki, and is the one who informs Yoshimori's family of his kidnapping.