Maoyu: Archenemy & Hero - S01

Fifteen years have passed since the war between humans and demons began. Unhappy with how slowly they are advancing into the Demon Realm, the Hero leaves his companions behind to push ahead quickly toward the Demon Queen's castle. When he reaches the royal home, the Hero finds something startling: not only is the Demon Queen a woman of unmatched beauty, but she also wants the Hero's help. Confused by this unexpected turn, the Hero refuses to ally with his enemy, saying the war the demons have waged is tearing the Southern Nations apart. But the Demon Queen pushes back, arguing that the war has not only united humanity but also brought them wealth and prosperity, and she offers evidence to back her claims. She also explains that if the war were to end, the supplies the Central Nations send to aid the Southern Nations would stop, leaving hundreds of thousands to starve. Fortunately, she offers the Hero a way to end the war while bringing hope not only to the Southern Nations, but also to the rest of the world, though she will need his help to make it a reality. Finally convinced, the Hero agrees to join his former enemy in her quest. Vowing to stay together through sickness and health, they set off for the human world.