After escaping a violent encounter, Touko finds herself lost in the chaos of a city under invasion by Spiders, a tribe of people with dangerous supernatural abilities. Touko has traveled to the city intending to return the possessions of Haijuu, a fire hunter who died protecting her. She is aided by Haijuu's dog, Kanata, and Akira, a fire hunter who has protected her on her journey so far. When Akira is drawn away by an important task, Touko is swept into the battle's confusion to begin a new journey of her own.

Meanwhile, Haijuu's son Koushi fights to defend the city. Though physically unremarkable, Koushi's ingenuity has aided in the development of a few useful weapons. These include a powerful cannon capable of casting down ungodly lightning to smite the invading forces. With such destructive force seen as an offense to the gods, the deity Hibari seeks to stop him.

As they are both drawn into the unraveling plans of scheming gods and humans alike, Touko and Koushi struggle to survive.