The Mu in Muichiro Though he escapes, Muichiro grows weak and numb from the needles' poison. Seeing Kotetsu about to be attacked and unable to move, his life flashes before his eyes and he regains his memories. The son of a woodcutter, he became orphaned after his mother fell ill and his father went out to get medicinal herbs, dying on his trip. His older twin brother Yuichiro, now cynical and bitter over their deaths, raised Muichiro but remained cold and distant from him. A visit by Kagaya's wife Amane to recruit them into the Corps only provokes Yuichiro, launching him into a tirade about the fruitlessness of helping others and how they are fated to join their parents in dying a worthless death. One night, a demon found them and mortally wounded Yuichiro. Muichiro, in a blinding rage, defeated the demon and witnessed his brother's last moments, apologizing to him and praying he will survive. The traumatic memories cause marks to appear on his face, augmenting his speed and strength. He rescues Kotetsu and makes his way to save Hotaru and Kozo. Gyokko, shocked he had escaped and with similar marks to Tanjiro, uses multiple attacks but discovers Muichiro can match him blow for blow.