So like You only stayed with her because she was the only one who put up with his crap? He keeps saying "She's always been with me" as the reason he stays with her. He never was like "I love her!" I also feel like he is struggling to let go and realize the fact that he just doesn't love her in that way. It's like they both just staying with each other out of obligation or it's really comfortable to not change. I bet even if he learned that Michi emotionally cheated on him with another man he would just like not even be half as motivated to do anything about it as Kaede is. That is worse. He is just with her because he's afraid he won't do better.
Him and Michi are becoming different people, but seem to be in denial about it.