A vagabond ninja who becomes an enemy of the Eight Demons of Kimon when he interrupts Tessai raping Kagero, ultimately resulting in Tessai's death. His talent rests in his expert swordsmanship being able to defeat a vast number of opponents by himself, and his sword has a wire attached to it to allow him to retract it to his hands should he be disarmed.

Senji used to be a policeman before his time in DW. He seems to thoroughly enjoy violence, and his favorite phrase is "Dead Center" (or in the dub of the anime, "Sssslice."). Despite his wild and battle-hungry attitude, he does have a sense of honor and respects strength and determination. His Branch of Sin is called "Crow Claw". It manifests as two large scythe-like blades, made of blood, extending from long cuts on his forearms. He makes these cuts using two bladed rings he wears on his thumbs. While the blades are typically two to three feet long, Senji has demonstrated the ability to greatly lengthen them allowing him to attack people at range. He also has a supersonic attack called Invisible Black.