Set a century before the main Code Geass story, this manga follows Renya, a seventeen-year-old fighter with a mechanical left arm and a set of throwing blades, in Edo-era Japan. When the ageless witch Reifū C.C. tries to grant him a new Geass covenant, the ritual goes wrong and curses him instead, right as a mysterious man who looks strikingly like Lelouch Lamperouge appears with his own hidden agenda.