Ikuseisou no Yoru o Koe

Kyoushirou, the mercenary, is cursed with immortality after a battle with a strange man, and after years of wandering in loneliness, he finds himself out of place in modern-day Japan. There, he discovers Tokino, who is the descendant of his former enemy. Though he desires revenge, can Tokino's kindness mend his tortured heart?