Not so serious Theory Time: These two are related
And Nobuta is the inferior and jealous one.
I mean not just because they share the same family name, but they also lowkey resemble each other. So cousins perhaps? Lol
Anyways it should be obvious why I think Nobuta would feel inferior to Kazuma. He's got the grades to be in Class A despite the competition there, athletic enough to be seemingly considered as one of 3A's ace athletes during the baseball match, which is also what makes him somewhat popular in school.
And it doesn't help that Kazuma loudly brags all those at every chance he gets.
Those are literally what Nobuta is lacking in and I think it could be a defining factor as to why he felt inferior enough to take it out on Class E students, who they were told to be traditionally inferior to Class D, to make himself feel like he's not the worst of the worst... you know, aside from whatever mindset Ono has been feeding onto his own class.
