The first prince and his fiancée, the daughter of a count, attend the Royal Academy. The two of them are of noble status and were engaged at a young age. However, because of Lilith's modest personality, she is mocked and looked down upon by those around her as the Iron Masked Lady. While everyone is vying for the position of the prince's fiancée, Lilith is secretly trained by the prince to be a princess. Her body is gradually remodeled by the yandere prince Finn, who wants to make her his own. The pleasure is so great that it even repaints her thoughts. Will she be destroyed by Finn's obsession and the limit of sex with love? Or...?