After a fight Hayate, Nagi heads to the apartment complex to hang out.  But her “little sister” is the only one home.  This might be Nagi’s chance to find out what Ruri’s real goal is. 
My youthful mind thought that 
was the worst reason ever.
A pesar de ser una niña, 
pensé que eso era terrible.
Aunque era una niña pequeña, pensé que era la peor razón que se podía dar.
Eu achava uma resposta
 terrível mesmo quando criança.