Yoriichi is a member of the Demon Slayer corps. He wore Hanafuda earrings like Tanjiro and is revered as the first breath user. He was the creator of the legendary Sun Breathing style, the style which other breathing forms originate from. Yoriichi have a older brother name Mitchikatsu Tsugikuni he is a member of demon slayer..his brother didn't betrayed him. His older brother use the moon breathing style. They both very dangerous to demon and the most strongest in the member of demon slayer.