In the medieval fantasy world of Alfheimr, Astarotte Ygvar, the first princess of the kingdom of Ygvar and a succubus, has just turned 10. During the coming years of a young succubus' life, it is necessary for them to have a male harem. To maintain their body and preserve their beautiful appearance, they must consume a substance found only on males. This substance is a liquid called "Sauzfryma", better known as semen. However, the princess bears a great dislike against men and only agrees to create a harem if a human male joins it. In the human world of Midgar, young father Touhara Naoya was greeted one day by a suspicious lady who claimed to be a fortune teller. She also claimed that she could help him find the "perfect job" suited for him. Although it seemed suspicious, he accepted the free consultation in order to support himself and his young daughter. After meeting the suspicious lady in the park a day later, he suddenly found himself in Alfheimr, a medieval fantasy realm located on a different world. The mysterious lady revealed her true identity as the Head Chamberlain of the kingdom of Ygvarland. He was then led to the palace of Ygvarland, where the "job" he had accepted was finally revealed: he was to become a human candidate for princess Astarotte's harem.