The story is told of Jukai-sensei, a doctor who not only healed the sick, but also made prostheses for those who had lost limbs in accidents or war. He once worked for Lord Shiba, crucifying wounded enemies until the day his loved one was killed by Shiba's soldiers and he leapt into the sea. He was rescued by foreigners and learned how to make prosthetics. One day he found Lord Daigo Kagemitsu's abandoned and limbless infant on a riverbank. He took the child home and later made prostheses for him so that he could move about and appear human. Six years later Jukai gave him the name Hyakkimaru. After Hyakkimaru killed the demon Kamaitachi and his right leg was returned to him, Jukai realized that although the boy attracted demons, his body parts were probably stolen by demons. Later, Jukai inserted swords into Hyakkimaru’s prosthetic arms before the young man left Jukai to travel alone. Back in the present, Hyakkimaru returns to Dororo and Houshi after killing a demon, but now appears to have the ability to feel pain. (Source: Revolvy)