Seri is the young heiress of the rich but socially-unremarkable Hatanaka family, set to marry her childhood friend, Yuzuki. For 12 years, she has been fighting against her parents' wishes of marrying Yuzuki for the financial benefit of both their families, adamant on having control over her own life. However, after she learns about the curse that affects the Furumidou family and discovers an ability to repel the evil manifestations, Seri begins seeing Yuzuki in a new light and wanting to protect him.