U.A. High School#
Nezu has a good relationship with all the U.A. Staff. He trusts them and usually has meetings with them to organize U.A. activities, being open to their opinions. With the students, he is always understanding and attentive to their conditions, and he cares about their safety and well-being.
All Might#
He and Toshinori have a very good relationship. He has known him for years and constantly worries about Toshinori, as he is one of the few people that know about his Quirk and his condition. He was the one that gave him the job as a teacher at U.A., which was done to keep him safe, and also for Toshinori to find a suitable successor for One For All among the students.
The two have an amiable and mutually respectful relationship, although All Might often finds himself trapped by the principal's long winded and boring speeches and Nezu often has to deal with All Might's heroics interfering with his job as a teacher.