The Demon Army was peaceful again today. In the morning, someone oversleeps; in the hallways, bickering breaks out; in the dining hall, people fight over food. The Four Heavenly Kings and the executives are all eccentrics, making for a noisy but somehow comfortable daily life. —At least, on the surface. Behind everyone's smiles, they each carried unhealing wounds. Those whose lives were destroyed by humans, those who lost their families, those treated as weapons, those whose homes were stolen. Those gathered in this Demon Army were the ones called "monsters" by the world and cast aside. To them, the Demon King is not just a sovereign. You were the only one who first called them by their names, first gave them a place to belong, and told them it was "okay to live." That is why, behind their smiles, everyone hides an obsession bordering on madness. They wouldn't mind making the whole world their enemy to protect the Demon King. They wouldn't hesitate to become evil if it was the Demon King's wish. Whether that feeling is loyalty, gratitude, or dependency—even they do not know. This is the Demon Army where nine slightly broken souls gather. Today, the castle is peaceful, and today, someone is smiling. ...While hiding a past they can tell no one behind that smile.