They took Loveriel injured in the battle against the devil. There, Loveriel told them the surprising things; angles in Heaven and devils in Hell have been fighting for a long time, and the devil would attack them again.
Because Loverel had lost her power during the fight, she asked Rika fight for her.
On the other hand, the devil had lost his power in the fight. Then, Otonashi Meimi, who was a classmate of Naoto, happened to come and see Naoto confess his love to Rika, and she became jealous. Taking advantage of her jealous, he haunted her. He made Meimi into an evil heroine, Misty, and made her attack Rika again. On the other hand, Loveriel turned Rika into “St. Jibril” and let her fight against them.