Objectively:
MC help Naoki (without him really offering ANYTHING in return) date multiple girls including a childhood friend
A new girl shows up and is only interested in Naoki (MC looks at her I guess? Does not have any thoughts about her though)
MC does not reply when Naoki asks if he likes her
Somehow not replying means yes? (ignore all the other things MC does not reply to)
MC crawls to daddy and gets "bullshit magic mind control" that will do whatever the plot requires (and only when it does)
MC starts "corruption" by going after the girl with the least amount of influence in the harem
Naoki did nothing wrong, MC is nothing without his daddy's magic mind control tech, and its pretty clear that this is just going to be your basic trainer/corruption game but instead of "a girl" replace that with "my friend girl"
Edit: MC comes off as a huge incel honestly with a random girl not paying attention to him (he did not make any attempt to talk to her), and her "stealing" his chair (which must be unassigned otherwise she couldn't take it) being enough for MC to plot against his "friend" for months in an effort to destroy his life,by brainwashing his own childhood friend and several of his classmates,