Criminal
Manji visits a priest in order to confess his sins, namely killing his lord and 100 of his retainers, an act that earned him the moniker "Killer of 100." The priest, who is actually a con artist, attempts to kill Manji by shooting him in the forehead, but Manji kills him and regenerates the wound. Manji returns to his home to find Yaobikuni, a nun who placed "sacred bloodworms" into Manji that make him immortal, and his sister Machi. That evening, Machi dreams of the time when Manji was forced to kill her husband, a police officer purusing Manji, causing her to lose her mind. After the dream, she wanders into the night and is captured by a group of ronin led by the brother of the priest Manji had killed. Manji pursues Machi but is unable to prevent her from being killed. In response, he kills every member of the ronin group, and upon returning to Yaobikuni, declares that he will seek redemption for the 100 men he killed by killing 1000 evil men.
Aired 14/07/2008EP 1 - Criminal

Blade of the Immortal
Manji is an amoral swordsman, who has been cursed with eternal life. He has grown tired of living with all the death he has created. He has no skills other then those of killing, thus he forms a plan to regain his mortality: he shall kill one hundred evil men for each good one he has killed. The old witch who afflicted Manji with immortality agrees to Manji's proposition and Manji is set on his path to kill one thousand evil men. On his journey he meets a young girl, Rin, who has her own vengeance to seek against the sword school whose members slaughtered Rin's family. Rin and Manji journey together, each hoping to find some kind of peace. In their way are many varied enemies. Rin and Manji are almost constantly under attack and must learn to live their lives, avoiding being consumed by revenge.
(Source: Anime News Network)