To say the least Neo is annoyed with Hae-Jin's uppity and flashy personality. He doesn't really get why he loves attention so much, and finds him to be an annoying person, often referring to him as a nuisance. Despite all this he finds himself always involved with him.
Raised as a noble Venia, Calanthia knows well of the prejudice against abnormal Venias. Though she did not come in contact with many when she was a child, she was cold to those she did see and treated them poorly, including Nikola. She was following the adults' behavior, acting how she believed she should. Now that she is older, she has come to not care as much or at least has made an exception for Nikola. She approached him for his research on plants because she runs a flower shop and also makes tea. While she put a bit of her pride aside to finally talk to him again, she is not humble enough to bring up or forgive her past behavior towards him.
Calanthia finds Nikola to be a great person to drink tea with since he's quiet...until he starts excitedly discussing his research. She has lost count of how many times he has gone off on a long rant about something new he discovered. Still, she finds him more interesting than some of the other stiff nobles, so she will listen to him even if it is about a topic she already knows. Sometimes she bothers Nikola when he is busy focusing on his work just so she can drink tea with someone. She enjoys receiving pelts and other things he collects for her from his Devora specimens, but she will probably never actually thank him to his face.