A Lady Must Know How to Kiss

Bibi had been working as a maid when she was suddenly brought to a nobleman's manor and told that she's actually the daughter of a famous noble family. There, she met the mysterious nobleman Kristoff, who announced that he would teach her how to act properly like a noblewoman and challenged her, having realized her competitive spirit. In her desire to get back at him, Bibi devises a plan and trains as hard as she can. However, she can't win against him and loses a bet that ends up in her losing her virginity! Bibi doesn't know anything about sex, so she's confused with the changes of her body that come with this unknown pleasure. However, the lessons continue with his strict guidance and sweet caresses... Source: MangaPlaza