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...
If you feel even a little responsibility,
Wenn ihr auch nur ein wenig Verantwortungs-
bewusstsein habt, dann werdet stärker.
Si tienen una pizca de responsabilidad, 
tendrán que volverse más fuertes.
Si sentís una pizca de responsabilidad, 
tendréis que haceros más fuertes.
Si vous vous sentez 
un peu responsables,
Se avete capito la situazione,
Se vocês têm ao menos um 
pouco de responsabilidade,
Если чувствуете за это хоть толику 
ответственности, вам нужно стать сильнее.