A Samurai's Requiem

Yuu Setsumi is a young samurai in training under the famed Ryuudo or as he is know as the Heavenly Demon Slayer. One day after a mission Yuu started to have these strange dreams of him begin carryed away by his past predecessors carrying him to a temple in the deep part of the holy springs, then Yuu would awake from his dreams, to reveal a mark of come kind on his left shoulder. He one day stumbles onto the temple in the holy springs after a failed mission, what will await him in the temple, why do the spirits haunt him and why does he bare that mark on his shoulder.

((srry i suck at summery s just read and find out))