User blog comment:TheBody84/Ichigos father being the former Kenpachi/@comment-1646325-20091015045520

Not sure what he was, but I don't think it was a Captain since none of the current captains (some of which been Captains for a long time) have ever remarked on his name or face. But, interesting enough, Ichigo does get away with calling captain commander "gramps" more than once.