Horrific monsters run rampant through the corrupt streets of Russell City while the populace thrives. Protecting the people is the Makai Order, a group of small business owners that hire Makai Knights and Alchemists to fight the evil creatures. Sword, a Makai Knight just given the title of Golden Knight, has uncovered a plot that could destroy the Makai Order. He only has one clue: a mysterious term called "El Dorado." During a battle with a Horror, Sword meets Sophie, a woman whose brother vanished years ago. Believing the disappearance is connected to "El Dorado," Sword and Sophie work together to uncover the truth behind her brother's disappearance and this ominous term.