Kensuke "Ken-chan" Nimura

About

The protagonist, an ordinary high school student who has had the ability to see ghosts ever since he was a kid. Because of this, he always felt different, but things changed after meeting Kagura. He started practicing kendo from a young age, being the son of a kendo instructor, and utilizes his skills during missions. When fighting, he sometimes dons a pair of sunglasses. The storyline concerns his growth as a spirit-user, his main weapon being swords. He initially wields "Michael #12," but after breaking it in a battle, is given the sword "Michael Revolution" in its place. He supports Kagura during her emotional lows, and a bond develops between them.
Kensuke has the same sesshōseki that transformed Yomi into an evil spirit, embedded near his heart. According to Yomi, the sesshōseki itself wished to be placed there. The stone gifts him with memories, as well as allowing his sword techniques to become radically more powerful. This stone was later removed when Imawano Setsuna forcefully tore it from his body in the Garden of Tamamo, fatally damaging his body in the process. He survived after Kagura defeated Setsuna and revived the Kyuubi, using its powers to restore his body from the brink of death. After firming his resolve to save Kagura from being controlled by the Kyuubi, he unleashes the true power of the Michael Revolution, the ability to cut through dimensions.
Kagura mentions that Kensuke has a unique presence which puts spirits at ease and even Byakuei feels more secure when Kensuke is near.

(Source: Wikipedia)

As of volumes 8 and 9, Kensuke developed a wound (and scar) over his eye after being attacked by a dark wolf demon.