Diluc convinced Jean to sneak out with him one night, wanting to take her out for a late-night drive after he received his driver's license. Unexpectedly, they both got into a car accident. Diluc believed Jean died in the accident and blamed himself for it. In reality, Jean survived the accident and got into a few days-long coma. After waking up, she has lost all her memories of what has happened before that car accident, including the man she loved. Several years have passed, and Jean hears rumors of a man that is moving into the apartment room next to hers. That man is Diluc.

A warrioress, fierce and true. Son of Hades, with powers anew. Son of Apollo, skilled in light. And daughter of Poseidon, with strength of might. A curse fell upon a demon child, a darkness so deep, wild and wild... At the heart of this quest lies a young demon boy, cursed with a darkness that threatens to consume him completely. Desperate for a cure, the demigods turn to the demon lord, the only being with the knowledge to save the boy. Time is running out, for with each passing moment, the demon boy loses a bit more of his humanity. With each step closer to their objective, the group of demigods becomes more entwined in a battle that spans realms. They must confront not only physical obstacles but also their own doubts and fears. The weight of the world rests upon their shoulders, and failure is not an option.