Tenri, Keima's childhood friend, has moved back next door to the Katsuragis.  She happens to be host to the goddess Diana, who tells Keima about she and the other 5 Jupiter Sisters once sealed away the Ancient Demons of Hell, the Weiss.  At the same time, the students of Maijima High School are excited because Kanon has made a rare appearance in the classroom for exams.  However, Kanon is preoccupied with the girl inside the mirror named Apollo, as well as the fact that she is being watched.
There's a demon standing over there.
No, después de todo tengo 
un demonio a mi lado.
No, después de todo tengo 
un demonio a mi lado.
Há um demônio aqui do meu lado.