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.

Knowing that the prize of the contest for White Lily Princess is demon incense that's harmful to demons, Aileen removes her male student disguise and enters the contest dressed as a woman. While others are overwhelmed by her beauty, James asks her to dance. The light dance steps of the pair fascinates the audience and Aileen is chosen to be the White Lily Princess. However, right after that, the mastermind has demon incense scattered throughout the venue. Aileen and the others struggle in vain as James turns into a demon.