A new series from Shinobu Ohtaka, creator of "Magi"! The setting is Japan's Warring States period, and the country has been conquered by demons. Two boys, Musashi and Kojiro, have made it their dream to form the strongest band of bushi and eradicate the demons. A one-of-a-kind Japanese fantasy! The only weapon that can stand against a Demon God is a demon metal sword. Only those who can successfully undergo a "katana test" and be chosen by a demon metal sword are able to join the fight against the demons. However, while Musashi is taking his test, a mysterious shadow deep in his heart appears and shows him scenes from his childhood. In order to move forward, Musashi will first need to turn back and face his dark past...