Shiba Isshin?

Every time I see Isshin, I can't help but notice how much he seems like a Shiba. He's got black hair, large amounts of reiatsu, and a habit of injuring his loved ones for no apparent reason--his battles with Ichigo look a lot like Kuukaku's battles with Ganju. And to top it all off, two of his three children also exhibit Shiba traits: Ichigo looks and acts just like Kaien-dono, and Karin looks and acts just like Kuukaku. (I guess Yuzu takes after their mother...) We know that Isshin used to be a captain before he left to hide in the real world, and that the Shiba clan used to be one of the great noble houses but "fell." Coincidence? I wonder...

He doesn't have the Shiba eyelashes, though.

Edit, Jan. 01, 2010:

A couple more Isshin-Shiba connections.

1. The Shiba are all named after two things: birds, and the element they use in battle. Kaien means "ocean swallow," Kuukaku is "sky crane," and Ganju is "stone/cliff eagle." Isshin's name, "one heart," doesn't follow this pattern. However, it's likely that when he left for the real world, he changed his name. In this case, the name "one heart" goes perfectly with Kaien-dono's view on life.

2. Urahara was banished 100 years ago, but Isshin only lost his powers 20 years ago. Why, then, do they know each other? It's assumed that Isshin is in one of Urahara's special gigai to keep Soul Society from noticing him, so he probably contacted Urahara as soon as he fled to the real world. My guess is that Kuukaku, who was very familiar with Yoruichi and Urahara before they left, might have helped Isshin contact Urahara.