Oof, Kotaro handing out L's and twisting the knife left and right w/o even realizing it this chapter. I do feel a little bad for the horny trio, but their past behavior is what caused the problem, and their current-day jealousy and aggressiveness isn't making things better.
My guess is that after fleshing out the main cast and having some romcom and slice-of-life shenanigans, the turning point will be Kotaro finding out the truth about his favorite e-girl. Cue him having a breakdown and losing his mojo, these three (and possibly sensei as well) stepping in to support and help him get his groove back, and repairing their relationship in the process.
...or vtuber turns out to be a rival if the author is feeling sadistic