As a scanner model, 9S is naturally curious about the world around him - especially the machine lifeforms. Usually working alone, he is deployed on the front lines with other S-type models, acting as YoRHa's main intelligence gatherer. According to A2, 9S is a "high-end model", meaning that he is one of the newest scanner types. As the newest model, he tends to dig deeper into YoRHa's secrets than his peers, often asking questions that those around him think he shouldn't be asking.