Astarotte no Omocha!

Astarotte Ygvar, a succubus princess and the first princess of the kingdom of Ygvarland, has just turned ten years old in the medieval fantasy world of lfheimr. For a juvenile succubus, the age of ten is noteworthy because it is when they are generally expected to create a male harem. Succubi who have reached adolescence must absorb male essence, just as a vampire must take blood, to preserve their body and keep their lovely beauty. A simple kiss will do at first, but as Succubi get older and become young adults, they eventually need to ingest a substance called "sáfryma," more commonly known as semen, to survive. They create harems to provide a reliable and secure supply of the fluid. But because she despises men so much and knows that they are extinct, the princess will only agree to form a harem if a human male joins. Naoya Tohara, a human male, and his daughter Asuha are brought to the monster realm to become members of Astarotte's harem after being discovered by the witch's minions.