Himekishi Lilia ~Mashoku no Oujou ni Otsu~

The main character Princess Lily-is the heir to the throne. However, it is not like her brother Prince Derek and he begins to intrigue, having signed a contract with the dark forces of the demons. Dirk found out that if you awaken the hidden power of the Lily, he will be able to get the most powerful army that the world has not seen before. However, to awaken the power of Princess Lily must achieve incredible ecstasy through sexual pleasures. Well Dirk will have to experiment to find the key to the secret secrets of Lily.