Reitetsu Ouji wa Dekiai no Soshitsu ga aru Kamoshirenai

When you come to, you find yourself in an unfamiliar room. Before you, an unfamiliar man. He says that he is a prince, and that he has summoned you to this world. His goal... to make you pregnant with his child. Against your wishes, you end up in a sexual relationship with this man... But after the first night, your relationship gradually changes.