My main issue was how fast kouhei jumped into a new relationship after just being dumped out of such an abusive one, and kei's method of trying to help kouhei was just very disturbing for many reasons. But I understand that they are both mentally unstable because of their previous relationship which brings me to a conclusion that both of them need therapy. Plus the fact that at the end kouhei confessed that he would try to help change kei other for the better puts me at ease because I think eventually kei would do the same for kouhei.
Sayonara, Boku no Goshujin-sama