The new shonen action manga from the creator of Magi is here! Musashi is a teenager living under demon rule. As children, he and his best friend made a promise: to become the greatest warriors in the world and overthrow the demons. But life intervenes, and five years later, he finds himself about to become a miner. Yet can Musashi truly be satisfied with a "normal" life?THE BELLY OF THE BEASTThe reassembled Obsidian Eight have launched an all-out assault on the Land of the Setting Sun. After speaking to Lord Hojo, Musashi and his friends learn that their best hope may lie in special black blades forged from the body of a demon god. Musashi and Kojiro then set off on a perilous journey into the bowels of the earth itself in search of the precious dark metal.