9S

She has 9S complete several sidequests for her that involve searching for relics of the old world, where she responds to the findings with interest on the relics pertaining to human familial behavior. Pronounced "two-one-oh." Calm and skilled at analysis, this operator was originally in charge of relaying messages to 9S. She personally requested to have her equipment transferred to a B-model for the drop, after which she joined the battle as 21B before going missing. She was eventually encountered again at the resource recovery unit in the amusement park ruins, where she had already been overrun by the virus. In the end, A2 had no choice but to take her life.

Pod 153 supports 9S.

Pod 153 has a robotic, observant, and stoic personality throughout the story. It is highly knowledgeable about science, strategy, YoRHa operations, and other related fields—expressing its thoughts and proposals using a logical and tactical mindset.

Pod 153 is loyal and protective towards 9S, willing to conduct whatever actions he commands despite observing how illogical they may be. However, Pod 153 can be secretive when necessary.

Digital hacking to destroy/control enemies, remote scanning for data, afterimage dodges, and managing electronic chests.

He can have a single blade on him.

9S has the appearance and voice of a teenager. He has short, snow-white, neatly styled hair, and when he removes his standard blindfold, pale blue eyes framed by fairly long eyelashes are revealed. His outfit consists of a trench coat with the YoRHa emblem embroidered on the hem, slit at the sides for greater freedom of movement, with large cuffs secured by belts, a pair of shorts, knee-high socks, and a pair of combat boots also secured with belts, all dyed black in the same leathery texture that all YoRHa units seem to have on their clothing. His accessories include a black choker around his neck with a square bearing an X attached to it, black gloves, and his signature green fanny pack.

He has a cheerful and lively personality and often expresses his emotions, which is why 2B frequently reprimands him. He is highly intelligent and has boundless curiosity, but he has a habit of getting involved in matters irrelevant to missions. Despite this, his talent makes him a reliable agent. He is also willing to risk his life to save 2B.

As a scanner model, 9S has a natural curiosity about the world around him, especially mechanical lifeforms. He typically works alone and is deployed on the front lines with other S-type models, acting as YoRHa's primary information gatherer. According to A2, 9S is a "high-end model," meaning he is one of the newer scanner types. As a newer model, he tends to delve deeper into YoRHa's secrets than his peers, often asking questions that those around him believe he shouldn't ask.

As a member of YoRHa, he harbors a deep distrust of the mechanical lifeforms that now inhabit the planet, a distrust fully revealed when an emissary from Pascal's village confronts him and 2B at the abandoned amusement park. Though he doesn't trust the supposed peace treaty, his overwhelming curiosity compels him to follow the machine to its home. As time passes, 9S's opinion of the machines shifts as he learns more about them, and he eventually develops a genuine concern for Pascal and his villagers. In Routes A and B, while competing in the Flooded City coliseum, he expresses disgust at the Resistance androids' treatment of the machines, which rivals the cruelty he once believed only humans were capable of. However, he can't help but wonder if there is a part of himself capable of such depravity.