This is a world built on the corpses of ancient giant beasts, with bones as beams and flesh as fuel. The glory of civilization all comes from the ghosts of giant beasts imprisoned in the "soul cage". Broken Oath is a knife that has self-awareness due to an ancient contract. His soul is imprisoned by the eternal marriage contract and is forced to become the future body of the sleeping evil god "Lord of Corruption". He just wants to "divorce" and regain his freedom, even if he becomes a mortal. However, the awakening of the evil god triggered the "God's Corpse Transformation" - the collective decay and mutation of the corpses of giant beasts, and the foundation of civilization began to collapse. To break the oath, he must walk with the girl who holds him, and cut a way out in the mountain of corpses and sea of blood: will he cut off the engagement and become the fuse of the destruction of civilization? Or should we face the truth, uncover the cruel reality that the "behemoth" is actually the incarnation of our ancient compatriots, and find the final rest for the two eras in betrayal and sacrifice? This is a story about a knife that confronts one's own destiny and the origin of the entire world.
