Responses

I think that Kouki didn't actually betray Nirasawa. They were talking about their plan being super risky. Also, after Kouki hit Nirasawa he dug through Nirasawa's clothes looking for the camera, but on an earlier page it was Kouki who had the camera. I believe this is what their plan entailed to get proof of Sagawa's involvement with Shao Chen.
I didn't expect that blonde dude to actually betray him, he better stab that old man and save nirasawa. Dang, what a let down.