Ichigo's dad (I dont know his name) use to be one of th gotei 13 captians (the white over coat), but Uruhara took his powers into storage. But they would have remembered him right? Rukia knew Uruhara was once a Gotei member why wouldn't she recognize Ichigo's dad, Renji would if she didn't. Im starting to believe he was Kenpachi's senior because of the way his overcoat is tattered. But that would mean that Kenpachi killed him? Which by the display of his power when he was rusty is impossible. Unless he planned it and then jumped ship with Uruhara's help before he was expeled. But then why would he go to earth unless he met Ichigo's mom before he left.
But what is confusing me the most is why did he show up only to save Kon in shinigami. He could have easliy asked Uruhara's men to pick up Kon if he new he was out in the world. Because i believe the guy in the glasses could destory an espada no problem with a sneak attack. Im thinking it was a plot device to extend Ichigo's story by giving him imbread abilites, but then again why didn't anyone notice and why didnt Gotei 1 send people to retrive him??