ahh i love it..the prequel is the third story of Sotsugyou Zenya

Probably it's just me, but I feel there should have something happened between prequel (Sotsugyou Zenya) and this series. See, mengaka hinted the union of Kazuhiko and Yuzuru. How comes the partner got changed, even with the guilty family breaking problem. Just a few flashback is really not enough.

I thought him and that young boy,and he didn't want him to break up that family? so yes I am very confused