Mirei, serving as the housekeeper supporting the wealthy Takiyama family, secretly developed a romantic relationship with Shoichi, the family's only son. Though drawn to Shoichi's kindness and warmth, Mirei kept telling herself not to fall too deep. One day, their affair is discovered by Shoichi's grandfather, Soji. Disapproving of the mismatched relationship between his grandson and a maid, Soji pressures his other son—and Shoichi's father—Takehiko to break them apart. The feelings that have blossomed between Mirei and Shoichi now threaten to shake the entire family to its core.