Webkokushibo's jealousy comes from his inability to escape his brother's overwhelming shadow. Yoriichi, the inventor of the sun breathing technique, possessed. Webbefore he became a demon, he was actually a human named michikatsu tsugikuni, who happened to be a demon slayer. He is the twin brother of yoriichi. Webkokushibo is one of only two known demon slayers who became demons later in life. His past is a dark and rather sad one weighed down by jealousy and an. Webkokushibo was a human during the sengoku era, and was the older brother of yoriichi tsugikuni. As a human, he was a powerful swordsman and respected. Webin the sengoku era nearly five centuries ago, kokushibo, originally michikatsu tsugikuni, was a human and the older twin brother of yoriichi tsugikuni, renowned as the strongest. Webwell, he was a breath of moon user; But since the moon always. Webkokushibo is the only demon who is capable of using breathing abilities, and his blood demon arts provide extra skills and powers, which is why he still maintains.
