Board Thread:Improvements and Issues/@comment-5355747-20130313062554/@comment-11051098-20130709223418

As far as I know, it's not been stated how long Isshin was a captain. I got the impression it wasn't more than a few years. So maybe people outside the captain and lieutenant ranks didn't see him more than a few times, if any, except in his own squad.

As for connections, I think Ichigo should know about his bonds to the Shiba clan by now, as Isshin have revealed his past to him. Ganju, on the other hand... seeing as their first meeting ended with a fight, and the second started with one, I dunno how Ganju will take it. Unless Isshin messaged Kukaku about telling Ichigo, and she told Ganju about who Ichigo really is.