Fourteen-year-old Ikuto Touhouin runs away to sea after a fight with his father, only for a storm to wash him off the ship and strand him on Airantou, a tropical island cut off from the mainland since the Meiji era. Found and nursed back to health by a village girl named Suzu, Ikuto learns the island's entire male population vanished in a fishing accident years earlier, leaving a community made up only of women who have never met a man his age. His arrival throws the isolated village into chaos.