Originally, Nia was curious towards Shido, the person who helped her escape from DEM. As a result, she used <Rasiel> to set up their meeting and even agreed to go on a date with him out of gratitude. Still, she did not believe that he could get her to open up to him. However, Shido incurred her anger by pretending to be her favorite character, Tokiya, and violating her privacy through security cameras.
Eventually, after they tied in manga sales, she used <Rasiel> to peek into the other Spirits' pasts. She found herself understanding how Shido's honest personality was able save the other Spirits. The bond developed between them during that short period of time was enough for Shido to successfully seal her and save her from certain death at the hands of DEM. Afterwards, she retains her gratitude towards him, though she still continues to mercilessly tease him at times.
Takajou-sensei is a fellow manga artist whom was once Nia's friend. However, Nia distanced herself from her out of fear that she would eventually use <Rasiel> on her, This caused Takajou-sensei to believe that Nia hated her.
The two ended up meeting again during Comico, where Takajou-sensei bought a copy of the manga that Nia was selling. During their short time together, Takajou-sensei stated that even if Nia hated her, she will always enjoy reading the manga she had written. After recovering from having her Sephira Crystal stolen, Nia announced to Shido about her plans of reconciling her friendship with Takajou.
Kurumi confronted Nia with the intend to make use of her Angel, <Rasiel>, to answer her questions about the First Spirit. Despite initially viewing Kurumi with caution due to knowing about her violent history, she still remarks that she is grateful to her for removing the security of the DEM ship transporting her. Despite saying that she won't give Kurumi any dangerous information, she ultimately relented and gave Kurumi the information about the First Spirit.
Out of all of the other Spirits' past, Natsumi's story in particular resonated the most within Nia's heart, especially Natsumi's words of wanting to teach Nia how beautiful friendship can be. After Nia is sealed, she is impressed by Natsumi's drawing skills and approached Natsumi about the potential of working for her as an assistant.