He is the Kenpei (Military Police) Banchou. Isaki is the executioner among the Four Emperors and he commands over most other, lower Banchous of the Dark Student Council. He is a psychotic yet very level-headed fighter who is obsessed with making his custom-made sword, Canaria, 'sing' in battle by cutting, smashing and gouging his opponents to death. He is quickly disappointed by weak opponents because they can't satisfy his blade and his own hunger for power. He and Iai Banchou once attended the same swordmanship dojo under Isaki Kenji's father, who was the master at that time. Kenpei Banchou killed his own master and father as he saw that he had surpassed him in terms of skill and power even in his teens.