It has been 100 years since the Battle of Sekigahara. The Nagatsuno domain and Koyama domain at the southern edge of Tohoku have been at odds for a long time. Soya Danjo , the Nagatsuno domain’s chief retainer, keeps invading and plundering the Koyama domain. His deeds trouble his sister Akane. One day, a young boy from the Koyama domain is covered with injuries after being attacked by an unknown monster. He escapes to a Nagatsuno village and is brought to Akane by the wandering samurai Sakakida Soei. The approaching monster strikes fear. Together with Sakakida and painter Kikuchi Enshu, Akane musters wit and courage to fight against the monster and uncover the mystery of its birth in order to protect her people.