in the evening by the moonlight

Harvey, the lone Martial King who sealed the Demon Cave for ten years, is publicly stripped of rank by Empress Phoenix after she believes the slander. But the seal breaks, and three demon lords escape and butcher the Rosefinch Empire. The Empire pins the blame on Harvey, ruining him and issuing a manhunt. Facing the Empire's collapse, Harvey at first stays out of it. When the Demon Emperor arrives, Harvey's sister, Yvette, is threatened, and Empress Phoenix begs. Harvey answers, returns with thunderous might, routs the demons, and rescues the Rosefinch Empire.