Who is the Japanese prime minister?

It occurred to me recently that I can't remember the name of the new Japanese prime minister, and not only that I don't even know what he looks like. I honestly wouldn't be able to pick him out in an identity parade. Prime ministers change here as regularly as teenage girls in Shibuya change their shade of nail varnish. Since I moved to Japan in 2003 I have no idea how many prime ministers there have been and would be hard pushed to name half of them. Maybe I don't need to get to know what the new one looks like - the new one will probably be along before I've returned from my Christmas holiday.