[It's a good question, and the answer is something he can't quite put into words. It's a little difficult to try, but he has to, for Mitsuzane's sake.]

Because you are my brother.

[His grip tightens briefly, holding him close, before he reaches up to brush the back of his brother's hair. He remembers doing this as a child.. hopefully it will help.]

Because as much as you have the capability to do terrible things, I believe that the path that leads to them is not the only path you can take. Because I believe... that you can do better. That you are better.

[Isn't that what Kazuraba Kouta had tried to tell him - that there was always hope? That even in the face of unspeakable tragedy, people could act better than they had before? That there was a better path than the one of death and tragedy?]

Because you are my brother, and I will always care about you.