2B/6O

2B/6O is the non-binary ship between 2B and 6O from the NieR fandom.

Canon
2B and 6O are both androids working for YoRHa. While 2B is a combat model, 6O is her operator. It is apparent right away that they are opposites in personality. While 2B is stoic and focused on completing her missions at all times, 6O is far more expressive with her emotions. During 6O's first in-game contact with 2B, she asks what the weather on Earth is like. When 2B states that her question isn't relevant to their mission, 6O laughs and teases 2B for her characteristic stoicism. However, it is also clear that 2B cares about 6O, though she is reluctant to show it. When 6O contacts 2B and tells her about being rejected by another operator whom she liked, 2B does what she can to comfort her despite claiming she is definitely not the person to talk to about this.

6O shows great interest in learning more about Earth, though she can't visit Earth freely like 2B can, due to her being an operator unit. She seems to have a particular interest in flowers, telling 2B about one kind of flower on Earth called a Lunar Tear, which she'd learned about after looking through the Bunker's records. 6O says, "I bet you'd look really nice if you put one of those in your hair, 2B. It'd suit your stylish looks!" Always pragmatic, 2B replies that she doesn't need it, though she does decide to send 6O a Desert Rose as a memento from Earth. After 2B finds a rose and sends a picture of it to the Bunker, 6O contacts 2B with her thanks, remarking that there must be a bounty of nature that 6O has never seen before. 2B replies that there is — lilies, cherry blossoms, daffodils, and lunar tears among other flowers. She tells 6O that she'll send more in the future if possible.

Later when 2B and 9S are attempting to escape the Bunker after it has been overtaken by a virus, 6O is lost to the virus as well. While they escape, 6O's voice comes over the intercom and thanks 2B for the flowers she'd given her, saying that the Desert Roses were beautiful. Her voice is glitchy and the rest of her words are unintelligible. 2B is visibly disturbed by this. It is up to interpretation whether the announcement was a memory of 6O's from the time of the Desert Rose sidequest, or if it's her final thanks to 2B, though many choose to believe the latter.

Fanon
2B/6O is quite popular within the NieR fandom. It is likely the second-most popular pairing in NieR: Automata, coming after the somewhat controversial ship, 2B/9S. Fans of this pairing find the relationship between 2B and 6O sweet and endearing, due to the "Opposites Attract" trope exhibited by the two characters. Some believe that 6O gives 2B a sense of balance and levity since the latter is often so serious. The fact that they are a combat model/operator pair ensures that they already share a strong bond. Other fans simply prefer to see these two as friends, or prefer to ship 6O with the Commander — a pairing which received some in-game ship tease.

As aforementioned, the main ship to rival this one is the semi-canonical ship, 2B/9S. Preference is given to this ship over the latter by fans who believe that 2B and 9S have an unhealthy relationship, due to the hidden nature of 2B's dealings with 9S. In a fandom with a predominately female cast, femslash pairings are also especially popular, which may constitute another reason why some prefer this pairing.

2B/6O is the second-most written pairing for NieR: Automata on AO3. It is the second-most written ship for 2B, and the most written ship for 6O.

Fandom
FAN FICTION

Trivia

 * The operator who rejected 6O was also female, meaning that 6O is interested in female androids. ("Oh, there's this operator I kind of liked, but when I asked her out, she turned me down.") This lends some credibility to shipping 6O with another female character. However, it is unknown whether 2B is also interested in females — though the concept of sexual identity is somewhat ambiguous in Automata.
 * Operator 6O is known to send 2B mail over the YoRHa server which is unrelated to their work; for example, she sends 2B messages about her astrology readings.