Neil Bowman[]
Nick beating up Neil's bullies.
Neil is Nick's younger brother. Although Nick loves and is loyal to Neil, their relationship is rather strained. When they were younger, it is shown that Nick often 'bullied' and hurt Neil. But Nick didn't mean it in a bad way, and just wanted to make him stronger so he could stand up for himself against his bullies.
When questioned, Nick dismisses his behaviour as normal, apparently seeing no fault in his actions due to the unsurprisingly violent upbringing of demons. Likewise, Nick fails to realise that Neil has grown to hate him, treating Neil's efforts to get back at him by pulling nasty pranks as normal, if not loving.
Lynn Angel[]
It is unsure whether Lynn is Nick's friend or enemy. Lynn and Nick are often seen arguing or fighting with each other, usually over Nick staying in 1031 despite not being a resident. They get into fights so much that the other residents of 1031 treat it as a spectacle, betting on who will win.
Despite this, they don't outright hate or avoid each other, and are seen cooperating on things such as household chores. They seem to warm up to each other as the series progresses, and hang out together outside of the apartment (although they still get into fights regularly). Lingzi has said that they originally created Nick's character so Lynn would be less lonely.
James Hoult[]
James is Nick's biological father. Nick is known to idolise and look up to his absent father, going out of his way to seek affection and validation from him whenever they meet. His positive view of his father originates from his childhood, when his mother told him that James left to be a hero to hide the fact that he abandoned them. She never had the heart to tell him the truth, and although it's hinted that he's aware of this, he still seems to believe that lie later on in life.
Crystal[]
Crystal is Nick's close friend, who he met at a camp as as a child. Crystal was often outcast for being a tomboy, but was accepted and defended by Nick. They have been great friends ever since, often seen causing mischief together due to their similar personalities.
Axel[]
Axel is Nick's ex-boyfriend and current friend, who he met at a party as Nico (his transformed female persona). Although their interaction was forgettable to Nick, Axel held onto it and pursued Nico. At first, Nick pretended to be Nico to distract Axel from his work since Axel's job as a reaper inconvenienced him.
After several meet ups, Nick found himself beginning to care about Axel's feelings. Feeling guilty about decieving Axel, Nick felt obligated to meet with him and, after a while, attempt to break up with him. These attempts were thwarted by Axel's personal AI called Tom, who knew Nick's secret. Eventually, Axel ended up breaking up with Nico due to personal insecurity. Axel still interacts with Nick under the impression that Nico is his sister.
Mr. Bowman[]
Mr. Bowman is Nick's stepfather, and he married Nick's mother when Nick was still a child. Neil, Nick's half-brother, used to be jealous of Nick as a child because of how well Mr. Bowman treated Nick, despite the two not being related by blood.
It doesn't seem that Mr. Bowman hates Nick at all, and is even friends with Nick's biological father, James Hoult.