▌Monkey D. Luffy
Nakama. Oh captain, his captain, etc. You'd have to kill Zoro in order to break his loyalty to Luffy. As it is now, there's no way Zoro would ever leave his bro's side.
▌Nami
Nakama. He's whipped by her. Always in her monetary debt, and he sort of pays for it by protecting her. She is important to him, though. As a friend, etc. A bit worried about her since she's from the past. Won't ever show it though.
▌Usopp
Nakama. A lot more confident in Usopp since he's from Zoro's point. Also kind of proud of him. But again, won't ever show it. He's kind of become a closer friend in the City, due to him being one of the only other Strawhats around for awhile. BROS.
▌Sanji
Nakama. Disappointed to see how weak Sanji's become in the City (in the domestic sense, really). Sanji's gotten better about it, but it's still concerning and Zoro wants it fixed pronto. But really, it's with Sanji's best interests at heart. Or so Zoro thinks.
▌Kuina
OH GOD YOU WERE DEAD AND HIS MOTIVATION FOR DOING EVERYTHING HOW ARE YOU ALIVEKLAJ;H
▌Haruka
Met her in the City and has been pretty protective of her since Day 1. Now that Mamoru's here, he's still kind of let a bit of that go, but visits regularly just to hang out around her. The easiest way to relate their relationship is to think of a big brother/little sister relationship. She's also the only person he can't really be all that angry towards.
▌Himuro
GOD THIS WOMAN. Seriously frustrates him to no end and they just. Cannot get along. But in the end, Zoro really doesn't dislike her. She protects and looks out for Haruka and seems to have a good heart. It's just… she's so frustrating.
▌Marceline
Hates her so hard. Drinkin all the Hateorade.
▌Beatrice
Oh my god he will kill her someday, just wait.
▌Geddoe
A bro. Mostly a drinking buddy and guy to talk about swords with. Zoro really likes him. Thinks he's chill and all.
▌Shiro
Rivals. Although Zoro sees him more as a sparring partner. He's annoyed at him right now since he knocked Zoro out with a headbutt after avoiding him for a whole fight. Dat's cheating bro.
▌Ggio
Doesn't know him all that well, but considers him a worthy fighter. Not as good as Shiro or Grimmjow or Mamoru, but good enough to pass the time.
▌Grimmjow
One of the better fighters Zoro has faced in the City and he has Zoro's respect. Even if he does want to strangle the guy for his attitude. Mad skilled bro.
▌Mamoru
Probably the fighter Zoro has the most respect for, which is why he's not extremely worried over Haruka. He's still suspicious, though and doesn't really enjoy being around the guy. But he'll probably fight him again.