Kato-055 was a long-time friend of Cody-033 and Caz-098. The three of them always worked together on assignments, and Kato was always the best shot out of the three. Kato had a tendency to go "lone-wolf" and try to do things his way. At first this was unsettling to Cody and Caz, but after witnessing his abilities alone, they let it slide in the end. Halsey considered Cody, Kato, and Caz the three most mentally unstable SPARTANS.