User blog comment:EmirK/About Kihara Amata's son and espers in Kihara family in general/@comment-128.12.95.107-20130712171745

So I had a theory that Noukan would be the #6. Yuiitsu's golden retriever. In fact, Noukan is supposed to be the smartest of them and most influential. Considering that we know of at least 1 level 4 Kihara and that others are very strong and that he is the most influential of them in many fields, I think he's the real #6. He was mentioned last book after all. This might be wrong, but I think he might be involved somehow. He does know about IB. He might have known through Misaki or something. He is supposed to be in the prime of his life. He might be the one that is Amata's son though I doubt it. But that might be referencing him. If so, we both agree :D