A young boy named Natsuki is taking a trip to a technology park with his older neighbor, Nanaka. Their ordinary day is shattered when the sky suddenly splits open and a black sphere of flame descends directly onto him, causing him to lose consciousness.

When Natsuki awakens, he discovers that five years have passed. The world he once knew is gone, replaced by a nightmarish landscape ravaged by monsters. The technology park and its surroundings have been transformed into a devastated wasteland where humanity struggles to survive. Natsuki finds Nanaka again, but she is no longer the neighbor he remembers; she has become a hardened member of a small group of survivors fighting for their lives against the monstrous threats.

Natsuki himself has undergone a significant change. He has awakened to a mysterious dark power that allows him to conjure black flames, marking him as someone unique in this harsh new reality. Armed with this dangerous ability, he resolves to go on a journey to understand what happened during his lost years and to find a way to restore the world to its original state.

The story follows Natsuki as he navigates this post-apocalyptic environment, confronts the monsters that now dominate the land, and grapples with the implications of his new powers. The central narrative arc focuses on his quest for restoration, exploring themes of survival, loss, and the weight of wielding destructive force in a world already shattered by catastrophe.