The pivotal year in the Battle of Sekigahara was 1600. Toyohisa Shimazu, a commander of the Shimazu clan in Satsuma, escapes by himself into the mountains after the tactical retreat, where he eventually finds himself in a corridor with endless doors. Before Toyohisa can ask Murasaki, a mystery guy he encounters there, a question, he is sent to the other side of a stone door. The commander travels to Places, a parallel universe where humans and so-called demons coexist. Toyohisa enters the conflicts of an alternate reality as a warrior with Nobunaga Oda, Yoichi Nasu, and other heroes who have arrived from various eras.
