Young princess Astarotte "Lotte" Ygvar is a succubus, a being that depends on men's life essence to survive, restore her magical power, and carry on the royal bloodline of the magical realm. As such, succubi must maintain a harem of men nearby. However, Lotte holds a strong aversion to men, which will endanger her life when she comes of age. To persuade her to accept her responsibilities, her attendant Judith Snorrevik ventures into the human world to find a male human that Lotte can stand.
Judith brings back Naoya Touhara, a 23-year-old single father who unfortunately leaves his daughter Asuha behind in the human realm. As the first member of Lotte's harem, Naoya quickly adjusts to his new surroundings, focusing on serving the princess to make her happy rather than viewing her with any sexual interest. Unfortunately, when his daughter is permitted to come to the magical realm, Naoya's relationship with Lotte quickly deteriorates. Still, he works hard to mend their bond.
But soon it becomes evident that Naoya's arrival in the magical realm is no mere coincidence. As his connection with Lotte deepens, fate begins to weave together the ties that bind him and everyone else in this enchanting world.