Bazett's barrier was supposed to prevent surprise attacks from the dolls, however Illya finds a little girl, Erica, sneaking into their school. For some reason Erica calls Illya "Onee-chan", and the two of them quickly hit it off. Meanwhile, a man claiming to be Erica's father appears. He seems kind at first glance, and while he came to pick up Erica, he's also...?!
So schools even have baths on the roofs!
¿Las escuelas tienen baños en la azotea?
¿Los colegios tienen baños en la azotea?
Il y a même un bain
sur le toit des écoles !
Le scuole hanno delle vasche da bagno
anche sul tetto!
Então escolas também têm 
fontes termais no telhado, é?