Rurouni Kenshin is one of the greatest anime shows I have ever seen. Actually, it's manga written by Watsuki Nobuhiro that was turned into anime, but unfortunately I have not had the privilege to ever actually get my hands on some of it.
The main character is Himura Kenshin, who was known as the legendary Hitokiri (assasin) Battousai near the end of the Edo dynasty. He killed many people in the process of helping to establish the new Meiji government. After the war, he decided to become a Rurouni (wandering swordsman) and dedicated his life to protecting people. In this way, he was going to atone for the sins of killing many people as the Hitokiri Battousai. The sword he uses is the sakaba, which has a reversed blade and thus prevents the wielder from killing. His sword technique is called Hiten Mitsurugi Ryu.
Rurouni Kenshin is (c) by Watsuki Nobuhiro, Jump Comics, Shueisha, Sony Pictures Entertainment, and Fuji TV.