After ending the battle against Zolgia, Basara regains his peaceful life with his two little sisters, Mio, the daughter of the previous demon lord, and Maria, her little sister who's also a succubus. As Basara pursues the preparations for the sports festival at school, one day he's attacked by a person being manipulated by magic. Recalling the strange gaze he felt at school, a suspicion of his begins to grow...
I thought you were returning 
to the demon realm.
Ich dachte, du wärst
ins Dämonenreich zurückgekehrt!
Creía que regresarías 
al reino de los demonios.
Creí que regresarías 
al reino de los demonios.
Tu n’étais pas retourné 
dans le monde des démons ?
Non dovevi tornare nel mondo dei demoni?
Você não disse que iria voltar
 para o mundo dos demônios?
Разве ты не вернулся в мир демонов?