Ichigo had a fair resemblence to Shiba Kaien, which was a member of the one of 4-5 royal families in Soul Society, however they fell from their status due to an unknown reason. Kaien had black hair though, and Ichigo has Orange-ish. It's been hinted that Isshin got married to a Quincy, because of his good relations with Ryuuken (Ishida's dad). The whole idea was that Isshin got married to a quincy and his whole family was stripped of their titles, and the real name of Ichigo's dad is Shiba Isshin. This makes sense, because Shiba Ganju (looks a lot like Isshin), and Shiba Kuukaku (the leader girl, has resembling personality traits to Ichigo/Isshin). Shiba Ganju said that "their uncle" would be mad because they let Ichigo go with the Royal Guards. It stands to reason that they mean Isshin. And it makes perfect sense, because Ichigo seems to have a connection to the Quincy side (Juha bach saying, "my son"). Ichigo is probably then a half-quincy because of his mother.