Byaku is one of the two main antagonists of the first half of the manga series Kekkaishi, and one of the two main antagonists of the anime. He is the second-in-command of the Kokuboro, and he is very loyal to the Princess, their leader.

He is voiced by Kenjiro Tsuda in the Japanese version of the anime and Roger Craig Smith in the English version.


Byaku has long, gray hair which usually covers the left side of his face. This hides his over-sized left eye, but still reveals a large, X-shaped scar centered on his nose. Both the left side of Byaku's head and most of his left arm are composed of mechanical parts. Unlike the other members of Kokuboro, Byaku is actually still human, though he has heavily modified his body.


While he was entirely human, Byaku rarely showed any emotion. He claims to have never loved his wife, believing that she was only using him to fulfill her own selfish desires. Byaku is a master manipulator, and remains calm in almost any situation. Though he rarely fights, in all of Kokuboro, only Princess and Kaguro have no fear of him. He is entirely devoted to Princess, and she appears to be the only one he ever truly cared for.


Byaku was once a completely human man named Shiranuma. He married a beautiful woman named Risa Kagami, and gave in to her every whim. Though she usually asked for luxuries, her greatest obsession was to always be beautiful.

Shiranuma performed several experiments on her body to that preserve her beauty, but one of them left her hideously disfigured. She took her own life, and in accordance with her final wishes, Shiranuma buried her and burned their home. He dug two graves for them, but left his own empty. Risa's body was dug up by Heisuke Matsudo, who had been in love with her. After fruitless attempts to revive her, he made a contract with a demon who agreed to take on her name and form.

Shiranuma somehow transformed himself into Byaku through heavy modification of his body, and came to challenge Princess in battle at some point, seeking her power in order to become an Ayakashi. He was easily defeated, and chose to serve her, becoming her voice in Kokuboro. He controls most of Kokuboro's leading Ayakashi with control bugs implanted in their heads, through which he can force his will upon them or cause extreme pain.

Powers and Abilities

  • Cybernetic Implants: Byaku is a cyborg: nearly all of the left side of his head is merely a mechanical nest for his worms, and can even be opened up at will. More than likely, these implants are either partially or entirely responsible for his control over bug demons.
  • Bug Demon Tamer: Byaku employs literally thousands of various demon bugs to do his bidding. He issues mental commands to them through his over-sized left eye.
    • Control Worms: Worms placed inside the foreheads of many Kokuboro demons as well as enemies. They record events through their host's eyes and exert varying amounts of control over the host's actions. Byaku reabsorbs these worms through his left eye, instantly taking in all data they have gathered. By dousing his opponent with the bodily fluid of these worms and then gaining their consent to a challenge, Byaku can create an invisible route to their body through a curse, causing near-total paralysis and making them easy prey for his worms. When this occurs, both his left eye and the areas touched by the fluid are marked with gaping, black holes.
    • Camera Bugs: Records and sends signals back to Monitor Bugs.
    • Monitor Bugs: Displays whatever scenes the Camera Bugs capture.
    • Transport Bugs: Gigantic bugs that can carry large numbers of demons into battle. They are usually concealed by huge, dark clouds during battle, since they carry the bulk of Kokuboro's army.
    • Announcer Bugs: Relays messages to all Kokuboro troops present.


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