College student Sota Akizuki is swept overboard during a violent storm and believes his life is over. When he awakens, he finds himself stranded on a mysterious island in another world. There, he learns that men are extraordinarily rare—only one is born for every thousand people. Because of this imbalance, the Kingdom and the Empire wage endless wars over men. In this strange world, men avoid women while women desperately seek them, creating a deeply distorted social order. Trying to conceal his true circumstances, Sota acts as he normally would, only to discover that his very "normality" is what makes him extraordinary. In a world where a man's sexual desire itself is treated as an overwhelming advantage, he begins captivating one strong and beautiful woman after another.