Set in an alternate 1853, Lelouch is is the commander of the Shogunate's military counterinsurgence brigade known as the Shinsengumi, which fights the Black Revolutionaries, a rebel group led by a mysterious masked individual known as Rei. An aternate-history retelling of the story of Code Geass!
When I bought this at the book store, I was told it was the first (and only) Code Geass. I read it and don't know what it's about now that I'm finished... It's manga, and no anime or manga is ever horrible, however. The reason for the low rating is just that I didn't understand any of it.