An ordinary Beta named Nao, one day, has a predestined reunion with that childhood friend who had long since moved away, this being an Alpha named Nagi. Beautiful and perfect, an Alpha that even resembles the appearance of a prince. And who, despite having grown so much, could still remember that [promise] they made as children. And Nao, being hugged so lovingly, can't help but feel her heart beat. But, during their long-awaited reunion, for no reason something inside Nao's body begins to react. [A zeal that should never have been presented since it was a Beta]. "Nagi-kun ... touch me" Is that a sign that Nao is that small probability out of a million people whose gender mutates to another ... ?! A wild and mischievous love story between an Omega X hating Alpha prince and an ordinary ex-Beta.