Manji, a recently-turned immortal swordsman, has sworn to kill a thousand villains to counterbalance the merciless and indiscriminate slaughter that ended with the death of his sister. To this end, he decides to travel with Rin, a young girl who reminds him of the sister he failed. She has sworn to take vengeance on the Itto-ryu, specifically their leader Anotsu; for the Itto-ryu are group of elite swordsmen who killed her parents and raped her mother in front of her. However; being immortal doesn’t guarantee victory: Manji’s skill and immortality will be tested to their limits...