Kaimetsu Kinzoku is an S-rank missing-nin from Iwagakure and a member of the Kinzoku Clan. He and his best friend, Akagane Enmaku defected after a failed attempt at the Fifth Tsuchikage's. They were chased by ANBU and bounty hunter for years, but murdered them without hesitation. They later were known as The Kinjutsu Brothers because of their use of the Iwagakure Kinjutsu. They later joined the Akatsuki (Yang) of their own free will, hoping they could change this world.