Mugen no Juunin

Blade of the Immortal is a Japanese manga series written and illustrated by Hiroaki Samura. It was serialized in Kodansha's seinen manga magazine Monthly Afternoon from June 1993 to December 2012, with its chapters collected in 30 tankōbon volumes. The series is set in Japan during the mid-Tokugawa Shogunate period and follows the cursed samurai Manji, who has to kill 1,000 evil men in order to regain his mortality.

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.