Russell City is a highly developed city. In this city that celebrates prosperity, a huge conspiracy that shakes the world begins to take shape. Soder, a man who immediately detects the trend of the conspiracy, throws himself into an unknown battle to uncover the conspiracy. But the only clue he got was the keyword "El Dorado". During the battle, Soder met a girl named Sophia. Sophia is also looking for the meaning of the message "El Dorado" left by her missing brother, the queen. Sophia lost her queen, and Soder also had a past of losing his sister. The two, attracted by the word "El Dorado", felt an invisible bond from each other and began to act together. In this way, their journey of intertwining hearts began.