The company president and his wife make an unexpected bold proposal in front of their subordinate couple, whom they've invited to their home. They suggest a swap, offering their wife to another man—but the chosen man is someone no one anticipated. The middle-aged men present gathered with the intention of swapping partners, and responding to the Enomoto couple's enthusiastic participation, new pairings begin to form. The wife especially enjoys multiple partners, and even the single male guest finds himself irresistibly drawn to her charm. Once again, a new relationship teeters on the edge of beginning.