Samurai Spirits

A malevolent spirit named Shiro Tokisada Amakusa attacks the land under the banner of Ambrosia, killing many, including the parents of a boy named Otsuna. Driven by vengeance, Otsuna uses sword techniques known as Kusudaryugan to confront Amakusa. He encounters Haohmaru, who initially remains indifferent to the destruction. After observing the corruption spreading among the people, Haohmaru changes his attitude and joins the effort to defeat Amakusa.