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...
You're cheeky for a little sister.
Du bist ganz schön frech
für eine kleine Schwester.
Eres una hermana muy insolente.
Eres una hermana muy insolente.
Tu es bien impertinente.
Sei una sorellina davvero sfacciata.
Você é uma irmã bem convencida.
Зазнаёшься, сестричка.