Lotte no Omocha!

Astarotte Ygvar (Rotte) is the princess of the kingdom of Álfheimr. Being a succubus, when she becomes an adult she will need to consume sáðfryma (semen) like any other succubi. However, an incident when she was younger has made her dislike men, which puts her future health in danger as she avoids making a harem of males to sustain her health as it's expected. Judit, the chief of staff of her manor somehow manages to convince her to start a harem, but Rotte only accepts on the condition of starting with a human male, which it's known to be impossible. But Judit manages to cross Álfheimr and bring Naoya, a human male, so Rotte, after meeting with him, has no choice but to take Naoya as a harem candidate, "his toy".