Many events have unfolded for Nagi Umino and Erika Amano: they were exchanged at birth, discovered their betrothal, and have begun cohabiting. The pair now live with Nagi's sister Sachi and his admirer Hiro Segawa. Even though the arrangement is strange and disputes are common, the household is gradually finding rhythm.
The tension between them fuels drama, yet a sense of camaraderie begins to emerge as they navigate responsibilities and bonds. The arrival of Nagi's childhood friend Ai Mochizuki in Japan throws a wrench into the mix. Ai abruptly announces her wish to wed Nagi; though he rejects her proposal, she remains determined to claim him alone. With four women surrounding him, each harboring their own feelings toward him, Nagi faces the challenge of clarifying his emotions and deciding what matters. Their intertwined lives promise both conflict and growth.
