Code Geass: Shikkoku no Renya

A 17-year-old boy named Renya, who has a mechanical left arm and uses shuriken throwing stars, crosses paths with a mysterious, ageless witch known as Reifū C.C. at the start of the story. C.C. has arrived in the Edo period of Japanese history in search of a new partner to form a covenant. At the same time, a man resembling the character Lelouch from the original series appears, his purpose and motives remaining unclear. The events unfold within the established Code Geass timeline but occur during a different time period.