Anyway, the manga revolves around a young man named Raizo with an unfortunate abnormality: he has a small horn on his forehead. He has a larger growth, however, in the form of a female ninja...and then several female ninjas...who proclaim him to be their master as well as the emperor of Japan. In reality, Raizo is a ninja-in-training without a lot of skill, which is naturally the formula for some chaotic times.
You might expect this to be some kind of bubbly cute moe series, but Tanaka's art is really nothing like that-- see the attached pic, which is considerably more bad-ass looking than you might expect from the harem-ish storyline setup. Del Rey's licensed it, so it's almost certainly worth checking out!
No word on when we can do that, alas. Ali just announced in the Del Rey Manga newsletter that we can expect it in Summer '09.