Code Geass: Tales of an Alternate Shogunate

Code Geass: Tales of an Alternate Shogunate (幕末異聞録 コードギアス 反逆のルルーシュ Bakumatsu Ibun Roku Kōdo Giasu Hangyaku no Rurūshu) is manga series and side-story of the Code Geass anime series serialized in Kerokero Ace. Set in an alternate 1853, Lelouch 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 masked individual known as Rei. It was released on a single volume on October 25, 2010, while the English version was published on May 10, 2011.

Plot
Set in an alternate history in 1853 with new characters, Britannia's Black Ships appear in the harbor of Uraga. Some years later, Lelouch Lamperouge — brother to a young blind girl named Nunnally — is the commander of the military counterinsurgence brigade known as the Shinsengumi, formed under the orders of the Shogunate to fight the Black Revolutionaries, a rebel group led by a mysterious masked individual known as Rei. In fact, these two organizations are one and the same, and they seek to combat in influences of Britannia. Geass is the ability to call upon and summon the armored entities referred to as Knightmares; Lancelot is one such Knightmare.