FourWinds website carries it. You can mail order from them (email their customer service and you will get a response). I bought mine from a local reputed nursery in NorCal who special ordered it for me - it took them 3 weeks to get it, but I got a good specimen with lots of fruits on it.
You can ask your favorite nursery or OSH (if there is one near you) to special order it for you.

ashleysf, thanks a lot for your response. I actually tried to order from FourWinds website, but it seems like kishu is out of stock becuase you can not add this variety to the shopping cart. I will probably try email them. Thanks again.
Anybody in the So Cal area knows a local nursery carries kishu now?

You should also try the Citrus forum. There are people there who live in in So Cal and they may be able to help you find a local nursery that carries it.
Andrew

Logee's has a Kishu.

Cath

It's been a couple of years since I lived in So. Cal. but just before I left I bought a Kishu from Armstrong in Pasadena. They had quite a few at the time; don't know if that's typical.

The trees they have came from Durlings and they had both dwarf and ultra-dwarf. Other Armstrongs may have similar. I would give one of them a call.

Also, but not exactly in your neck of the woods, Green Arrow/Green Thumb in Ventura always has a large stock of citrus from Durlings. Maybe the ones in SF Valley do, too--I never thought to look there.

I wouldn't waste your time or money on Logees. Especially living in California. I also am pretty sure that they cannot ship citrus to CA. There prices are ridiculously high and there plants aren't worth sh*t! Trust me, I KNOW!!
I bought a 'Day' avocado from them last year. The tree was around $35 and was only about a foot tall. You living in California can do way better!!
Andrew

Logee's sells rooted cuttings, not grafted citrus trees. So, in effect they are not "dwarf" trees and you are not getting any of the benefits of grafting - that is besides the point - as Andrew says, they cannot ship citrus into california anyway. Another source that has good quality trees (Kishu included) is Menlo growers. If you cannot get FourWinds Kishu because they are out of stock, try to get your nursery to order it from Menlo growers.

Just for the record: I understand that Andrew has not been satisfied with Logee's. My experience has been different. Although the citrus plants, for example, have been smaller than Four Winds' at the same price, they have grown well. Moreover, I have not been totally satisfied with Four Winds' citrus. Spring of 2009 I bought 4 that arrived looking very good. Two have grown very little. Another had a bad graft with the top and bottom ends sticking out that took a year to heal. The last has grown very nicely. I have never grown dwarf citrus before and so I may be expecting something of them that they do not deliver. I am not totally panning Four Winds. I would order from them again. Hope my experiences help someone.

Cath