It has been half a year since Aini Mikkola, the saintess in training who hails from a barony in the countryside, arrived at the Royal Academy. The school is in turmoil.

The boys, the sons of aristocrats, are at the mercy of Aini's innocent, natural cuteness, while the girls are angry at her disregard for the manners of the aristocracy. In the midst of all this, there were three daughters who were dubbed "the villainesses," in reference to a popular story. Seraphina, the crown prince's fiancée and the daughter of an upright marquise. Sandra, the noble daughter of a viscount who made their wealth from commerce. Bernardetta, the brilliant daughter of the current Prime Minister's who is a marquise. When a sense of disquiet begins to grow in the school, these women finally stand up! To correct Aini's mistakes and to follow their own hearts.