The Blue World, representing reason, faces constant attacks from creatures known as the Nightfly O'Note, which originate from the Red World, a symbol of instinct. Akira Asagi, the 17-year-old protagonist and a researcher in the Blue World, is selected to command the war effort at Ryuukyuu LAG, a prestigious defense facility located on the islands of Ishigaki and Iriomote. She encounters the sixth combat unit, "IS," which was established four years after a brutal battle that wiped out the fifth unit. Akari must guide these six riders, also referred to as the Scared Rider Xechs, in their fight against the other world while simultaneously strengthening the bonds among them.