Koji Noshimuri is a man who appeared in Ke Kinohi and is responsible for the death of Doris McGarrett, John McGarrett's wife and Lieutenant Commander Steve McGarrett's mother. He was killed by Wo Fat, whom was tying up lose ends.
He is the brother of the former head of the Yakuza, Hiro Noshimuri and the uncle of Adam Noshimuri (CI, Five-0 Task Force Special Division of Organized Crime) and Michael Noshimuri.