Adachi was born a warrior as he was the son of Senji Adachi the highly esteemed leader of the village army. Adachi never knew his mother, although she was believed to be dead, as he grew up with no one but his older brother and father who was seldom at home. At the young age of 7, Adachi began his long training to become the village's next top warrior with his brother, who both were taught by their father, Senji. The boys were put through typical survival training and sparring overseen by Senji. As Adachi matured, his father found out that he didn't experience pain. It was an odd discovery but to test the limits of his pain endurance, Senji sliced Adachi's eye to get a reaction. Adachi hardly budged but blacked out from the loss of blood. This proved that he was very much susceptible to death but he felt no pain. His eye was replaced with an artificial one, a week later. Through extensive training, Adachi was prepared for exclusive orders for the sake of the village. Upon battle it was as if Adachi could perceive the exact distance between himself and enemies and react with perfect timing to avoid fatal blows. He possessed flawless perception of objects and judgment of his abilities in relationship to those objects. Adachi proved to be very intelligent as he often baffled people with his ability to describe the relationship between two objects with mathematical terms. He also mastered eight different languages simply by studying them in his free time. Adachi grew to be very popular in the village as he was expected to be the village's next best warrior. Before they could officially join the army Adachi and his brother had one more test. Senji took them to a remote location and gave them their final order. They were to fight to the death. The final test was to measure loyalty to the village. Adachi won the fight but refused to murder his older brother. Senji was not amused as he ordered Adachi to kill his weaker brother or he would do it himself. Adachi couldn't bring himself to do it until his brother told him it was ok, to free Adachi of guilt. Adachi had no choice, he killed his brother and became the village's newest warrior. The post syndromes of killing his brother ate away at Adachi as he slowly started to loss his sanity. Although he couldn't feel pain physically, the mental pain cut deeper than any blade could in Adachi's mind. Having never experienced pain before the magnitude of the mental pain tore apart Adachi's mental state. He began talking to himself and even referred to himself as being one with pain. He claimed to be the pain and it consumed his every thought. Adachi soon after abandoned the village and swore he'd seek an answer for the pain that consumed his heart. Thus began the story of Adachi.