Square Enix announced a while back that its 3DS RPG that's still named Bravely Default Flying Fairy would be getting a second demo at some point. Today, we have a few details via Jump (and early Jump getters, Tales Source).
The demo is titled Demo + AR Vol.1 - Crystal Maiden Volume. The AR part of the titel is presumably a reference to an AR component similar to that of the first demo. The "Crystal Maiden" of the title is a 17-year-old girl named Anies. She controls the "Wind Crystal" and sets off on a journey, lead by the Crystal Spirits.
Jump does not list a release date for the demo, but the fact that they're mentioning is probably a hint that we won't have to wait too long. Expect to hear something next week, after the latest Jump hits shops.