I love shiba inus. They are small, clean looking, cute as hell, and I'm told they are like a cat in a dog body (as a cat person, this works for me). But I've never actually had one and a friend told me they had rotten attitudes.
The ones I knew had a lot of energy and seemed to need a lot of attention-- beautiful dogs. There is a hubber who knows a lot about them and might be able to answer some questions: http://shibashake.hubpages.com/
I used to volunteer at an animal shelter walking dogs, and personally I'd rather walk a pit bull than a Shiba inus. The shibas that I worked with were very temperamental and somewhat snappy. It was the first and only dog that tried biting my hand. I'd recommend that you do your homework on the breed before making any decisions.