I think Kou is still rooting for Amane and Nene because of those last pages. Maybe we will know the reason for the break up because of Kou, just maybe. But idk if I still want Nene and Amane to get back together, I already hate Nene for what she's doing. Fuck Nene.
Lastly, I hope the reason for the break up is not Amane's fault