Why and when did ishihara...
Turn on mizuno and the boss? The was really out of left field, at least to me... Did I miss something? And why did he even bother to take that guy with him? He could of let him die in the explosion
shareIf he hadn't taken him with him, they would have known something is wrong. So why shouldn't he take him? He already knew that this guy was ready to also betray people(remember how he asked for a cut?), maybe he thought that made him no threat?
As to why and when...I guess Kato or someone approached him since he clearly was a gifted talent(for instance his brilliant English) and so the Kaicho thought he could be useful to the family and killing him would only be a waste?