Samurai Deeper Kyo, Volume 1 — Akimine Kamijyo

It is 1604, four years after the Battle of Sekigahara, Japan's greatest civil war. Yuya Shiina, a beautiful bounty hunter, mistakes a traveling medicine seller, Mibu Kyoshiro, for the legendary wanted man Demon Eyes Kyo. As they travel together Yuya enlists Kyoshiro's aid in capturing a gang of wanted criminals. When Kyoshiro is cornered and beaten senseless by the criminals his eyes turn blood red. The peaceful Kyoshiro draws his sword and transforms into Demon Eyes Kyo, the legendary killer of a thousand men. Kyoshiro and Kyo: Two vastly different spirits inhabiting one body.