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...
but before that, I wanted 
to give you all a warning.
aber zuvor wollte ich euch warnen.
Pero quería darles una 
advertencia antes de marcharme.
pero quería daros 
una advertencia antes de marcharme.
Je voulais vous avertir 
avant ça.
ma prima volevo mettervi in guardia.
mas antes disso, eu queria
 dar um aviso para vocês.
Но сначала хотел вас предупредить.