This may sound strange, but I have little to no romance in my novels / comics. Yes, they are science fiction / fantasy and the stories revolve around a lot concepts and occurances, and one could argue that romance should be a part of everything, but I've always kept romance secondary.
However, relationships I have definitely kept consistent: whether it's friendship or animosity.
My two mains do not like each other (at the moment), as is evident by this scene:
SPOILER: But once, a very long time ago, when they were kids, they were friends indeed. This will come later on in a few chapters.
I had touched upon Zov'ha's teenage romance in one chapter as a flashback, but that's about it.
Zov'ha's so focussed on trying to find herself and Aekis is so busy being... well Aekis. They don't have time for romance. They probably will never like each other, but they met along as friends.
As for the other 3 characters:
Marana: Her history with her girlfriend will probably impede any romantic relationship for a while. But guess what guys, I have a whole separate novel (or comic) coming in the future which is a proper GL of Marana's past life
Subeya: the 9-foot Poban? Well I haven't though much about her, but the big girl may find someone.
Sinovan: He's in his fifties. Let's just leave the man alone. He's just a kind soul.