First-year high school student Rikka Minazuki loses her will to live after she hears the dying words of her beloved father. However, on her sixteenth birthday, a young man who calls himself the Head of the main family appears and tells her that he has come to welcome his “betrothed” Rikka. “Although I am bound to this marriage by ties of blood, I believe that it is possible to find love.” In his words, Rikka finds a faint hope – House Minazuki: the descendants of a celestial maiden. Bearing the fate of a special clan on their shoulders, the two begin a true romance.