Not much is known about the game’s story as of yet, but dragons and song will play a large role in the game. Gematsu has posted some additional information, and according to their translation, the game is only about 5 percent complete at this point and your party can have up to four members.
The game’s protagonist is a apparently a dragon named Kouryuu Illban. His human allies can play melodies with a special instrument to cause him to attack their foes.
You can find more information about the game at Gematsu.