Rotte no Omocha!

In a medieval fantasy realm called Alfheimr, a ten-year-old succubus princess from the kingdom of Ygvar requires a harem of males to sustain her beauty by consuming a substance known as "Sauzfryma," which is found only in men. Astarotte strongly dislikes males but agrees to include a human in her harem. In the human world of Midgar, a young father named Touhara Naoya meets a mysterious woman who calls herself a fortune teller and offers him a job. After accepting her offer, he is transported to Alfheimr, where the woman reveals her true identity as the Head Chamberlain of Ygvarland. Naoya is brought to the palace, where he learns his job is to serve as a human candidate for the princess's harem.