The Viscountcy of Lane, cut off by dense fog, has endured countless sieges by monsters. A young knight's squire is gravely wounded in his first battle against a demon and only wakes after three days in a coma. Those three days become the beginning of his path to becoming a glorious hero. For no one knows that his heart has vanished from his chest, replaced by a majestic, imposing castle!
With humanity's main city in his hands, he will forge glorious achievements. Darkness may envelop the world, but the Castle Heart will never die!
