Mugen no Juunin: Immortal

Edo, an era of warriors: the immortal, Manji, the Hundred Killer, meets Rin, a woman who has sworn to avenge her parents and is looking for a group of swordsmen - Ittou-ryu. Rin asks Manji to be her bodyguard during her journey. The man refuses, but in Rin he sees his dead sister. Thus begins the battle that will bring the immortal Manji to its knees.