Aileen overcame all the difficulties and got engaged with Claude. Just when she thought she found her happily ever after, she receives news that a demon named Ashtarte attacked a human village in the Mirchetta region. Sensing new dangers, Aileen infiltrates Mische Academy in the Grand Duchy of Mirchetta to investigate the situation. There, she meets James Charles, the last boss of Regalia of Saints, Demons, and Maidens 2 as well as the other quirky members of the student council.
James, a half-demon, should have been 
the next Grand Duke of Mirchetta...
...كان ينبغي أن يكون جيمس، نصف شيطان، الدوق التالي لميرتشيتا
James ist ein Halbdämon
James, um meio-demônio, deveria ter sido
o próximo Grão-Duque de Mirchetta...