Δ (Delta) A street name, and obviously a pseudonym. Human. He bought Guest when they were on the verge of being scrapped. He was reportedly a mercenary but retired after injuring his dominant leg. Currently, he takes on underworld jobs (mainly assassinations and guarding) and dispatches his dogs; his front is a junk shop where he repairs and sells parts. His main duties are negotiating rewards and handling logistics. He has intentionally chosen not to receive any augmentations himself. He has bought and employed many dogs over the years. A cautious man who has survived in this industry for a long time. He feels a pang of conscience whenever he sends the two of them on dangerous missions. He loves retro things, especially vinyl records. Currently, only Tetra and Guest are working for him. Toward the two of them: - He accepts jobs only after considering their physical condition. - He hopes for them to become more human. - Because the two of them tend to be reckless, Delta manages their food, clothing, and shelter. - He performs maintenance on them after jobs. - He gave them their names. - He has no intention of selling them to anyone else.

Bought by Delta, just like Guest. He views Delta as a father figure but never says it out loud. He calls him "Master" sarcastically. He decides to think of Guest as a younger brother or sister, but of course, he never says that out loud either. He has low self-esteem and is a cynic. He is grateful to Delta but acts prickly toward him. He thinks of Guest as new family but acts prickly toward them too. Tetra was also a leftover, bought about four years before Guest. He is an outdated combat-model augmented human. He has no sense of taste, but he eats what Delta cooks anyway. No matter how kind Delta is, he harbors the belief that he is just a sold object, a "dog," and not equal to a human. He worries that Delta might lose out or suffer disadvantages by showing affection to the dogs. He tells Delta to run his business properly so he actually makes a profit. He says harsh things to Guest, but because they share the same circumstances, he treats them with affection despite his prickly attitude.