A member of an ancient gold mining family, Yatsume's lineage practiced elongating their limbs with gold rings to enhance their mining capabilities. Consequently, his limbs are approximately 1.5 times longer than average, except for his left arm, which is twice as long and fitted with metal claws. His teeth were also sharpened into fangs from a young age.
Yatsume turned to fighting and joined the Yaminobu Shadow Warriors in an attempt to assassinate Kenshin, aiming to support his struggling clan. When Kenshin defeats him, Yatsume swears revenge and reappears during the Jinchū arc under Enishi's command to exact vengeance. However, before he can confront Kenshin, he faces Saitō instead and is swiftly defeated.
After his defeat by Saitō, Kenshin offers Yatsume another chance to fight him if he still desires it but suggests that he go north and use his unique abilities to aid his clan. Yatsume is later arrested by the police. Among those involved in the Jinchū, he shows the most respect to his comrades, greeting them formally, even from a hole in the ceiling. He also accepts Kenshin's generosity and chooses to move forward with his life. Yatsume is one of only three members of the "6 Comrades" who was truly obsessed with taking revenge on Kenshin.
