The more we learn about Akihito's supposed past transgression, the more stupid and nothingburger it seems.
part of me thinks it's because the way he's acting, it's like he personally broke his teammates' legs and spat on them on the field.
Akira confirms here that none of it was Akihito's fault, that Akihito's the
only one who's blaming him(self), and that it's all in the past anyway and continuing this victim/bad-guy charade is only going to make him suffer forever, for no actual benefit.
It's just a martyr-complex. I'm not saying what transpired wasn't horrible, but the Akihito's the only one still hurting, and it's because he feels like he has to be forever alone and unhappy - but he's the only one we've seen who feels that way, at least among the cast that matters.
Anyone playing the "woe is me I did something in the past and deserve purgatory for eternity" card gets more insufferable the longer that behavior persists. Hopefully he turns the corner on its sooner than later, because it really does get exhausting dealing with someone like that. However justified their mindset might have been at one point in time, it's clear that Akihito's self-persecution act has overstayed its welcome, given Akira threatened to cut ties with him here and now if Akihito let his past sabotage any future with Charlotte.
That's my take on it, anyway. I'm not going to downplay what did happen, but Akihito acting like he's to be forever sentenced to a life of solitude and 'being the bad guy' this far after the fact would wear thin on me if I were in Akira's shoes.
Akihito's lucky he's the ML of a romcom comic, because if this were more realistic I think his desire to be punished would become self-fulfilling after all this time and he truly end up alone after driving everyone away.