Board Thread:Questions and Answers/@comment-10797017-20130620073556/@comment-11051098-20130729080038

I too doubt he's a Shiba. If he was, I see it unlikely that he would have changed his surname. He wouldn't have had any reason to hide from anyone, thus changing name would be pointless.

I think it's possible that Kirinji was one of the first 13 captains, but Hyôsube seem to be THE senior member in the RG, so I hold it likely that he too could have been that. And if he invented Hakuda or Kidô like someone proposed, that could be a big enough contribution to earn him a place in the RG. We don't know how long any of the RG members have had their positions, except Hikifune with 111-112 years.