The man that crafted the Demon Blade, using his knowledge of Muramasa and Masamune techniques. Kaji was cursed along with Mai and Shin Yoku. A poor swordmaker whose life’s work was denied made him to survive on crafting nails and tools within the town and became a town drunkard. Kaji began to despise the Shogun’s actions against his way of life. This only became greater rage when His wife and son died of a spread of influenza, when he felt that if he was allowed to make swords again, he would have the money to save them.

Tempted by Yoku’s offer and large supply of coin. He followed the fallen Samurai to Hokaido. Focused on crafting his masterpiece, he was unaware before Yoku tossed Mai’s heart into the fire to enhance the blade with magic. When Mai came seeking her heart, Kaji realized his folly and decided to repent after the curse befell them all. As Kaji followed Yoku after Tetsu found the blade. Kaji, along with Yoku, learned of ways to possess a body as it’s near the point of death. Once in Wintchell, he discovered the dying body of a young girl named Ruth Turtle and her crying father in fear of losing her. Kaji reflected on the fact he could do what couldn’t be done for his family and, in a quick action to prevent the soul of the girl from leaving her body, he ended up trapping and binding his soul to the young girl.

Once Tetra discovered the secret within the young girl, Yoku took action, trying to make amends to Mai and agreeing to do what he can to make amends for his part in making the sword. Yet, being a soul out of his time, he doesn’t fully understand modern stuff, and while he teaches Ruth, in turn, she teaches him of life in current times.