User blog comment:Godisme/The Gotei 13 repeat and reboot wrap up/@comment-7136323-20130404171427

Wow.... a lot of spoiler there. I can't wait to find out what happens. But, to be honest, i completely did not expect Aizen to come back, or even for this to be the last Arc. Yes, Isshin is a art of the Shiba clan. He was the head of the Shiba clan. His squad members even called him, "Captain Shiba." This was revealed in the most recent manga chapter, as of April 4th, 2013.