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. 
What happened? 
Why were you screaming?
¿Qué pasó? ¿Por qué gritaste tan alto?
¿Qué te pasa? ¿Por qué gritabas?
O que houve? Por que
 você estava gritando?