Nishinoya and Azumane have a strangely complicated relationship. Nishinoya deeply trusts and admires Asahi. However, the latter’s low spirits and utter lack of self-esteem often set the enthusiastic libero off, and have been the cause of some serious friction between the two. Nishinoya believes it is his personal responsibility to point out his senpai’s flaws, resulting in Azumane feeling more disheartened. At the same time, Nishinoya tries to support and encourage him as much as he possibly can, and becomes exceptionally flustered and apologetic if he fails to receive a ball in the ace's presence. Asahi, on the other hand, adamantly refuses to put the blame for any missed shots or lost games on Nishinoya, and is instead quick to marvel at his underclassman's passion and advanced abilities. He has even gone so far as to call Nishinoya "a seemingly perfect player" and wishes to improve himself so that he doesn't let him down in their future matches.
As a result of their similar personalities, Tanaka is probably the person Nishinoya gets along the best with. Aside from nonstop goofing, the two work quite well together in games. Tanaka holds Nishinoya's skills in the highest regard and takes pride in having him on his team, never failing to compliment him on a successful receive. They both have a crush on the volleyball club's manager, Kiyoko Shimizu, but instead of being rivals, they actively team up to "protect" her from any potential "outside threats" (namely boys from other schools). They also hate people like Oikawa who gets more attention from girls.They appear to be very close, as Nishinoya is the only second year that is implied to keep clothes at Tanaka's house (or else be comfortable enough wearing Tanaka's own), as seen during the second year study session. They are nearly always shown sitting together on the bus and are the only two characters to have slept on one another's shoulder, and their usual celebratory method involves Nishinoya allowing Tanaka to lift him high in the air in often ridiculous poses.
Nishinoya provides Hinata with lots of practical advice, both on and off the court. He has openly admitted that he considers his underclassman to be a genuinely good person and an amazing player. In fact, Nishinoya felt so touched when he first heard Hinata call him "senpai" and "awesome" that he not only volunteered to teach the latter the proper way to receive but also offered to buy him two popsicles. Nishinoya has also stated that Hinata is one of the few people that truly understands what a libero is: someone who's good at receives. (Most people think being short equates to being a good libero). Nishinoya is one of the few people who call Hinata by his first name.