To reach the stage of "FES.", Yukina Minato decides to form a band. Each holding their own convictions, the members of the band come together. The five girls now begin their journey to the top as Roselia... This is the story of their "promise" made to each other, from the start of the band to their challenge towards FUTURE WORLD FES!

The world of Lingalind is surrounded by a mystical wall with seemingly nothing beyond its confines. Worshipped as the mother of the land, the wall delivers celestial gift capsules called "Rakuho'' to locations across the continent. Arriving once a month, the capsules contain metallic armbands that allow the wearer to transform into a mechanical being known as a "Briheight." As a result, Lingalind is thrown into constant turmoil by its warring nations, all hoping to strengthen their military prowess by procuring the offerings for themselves. One day, a Rakuho crash-lands in the countryside with an unexpected inhabitant—a mysterious black-haired man. All eyes are set on this strange newcomer, who calls himself "Back Arrow," when he claims to have hailed from a place beyond the wall—a revelation that can potentially unravel Lingalind's entire dogmatic foundation. [Written by MAL Rewrite]

In the first season of B: The Beginning, two men confronted their own past with great sacrifice. Maverick detective Keith Flick fought against his demons and finally exposed the dark secrets behind the Kingdom of Cremona. Mutant wunderkind Koku finally reunited with the most precious memory from his stolen childhood. Several months have passed since then, and the entire world seems to have forgotten the turmoil caused by those events. As Keith returns to the Royal Police to conduct his own investigation, Koku and Yuna try to enjoy an ordinary life in peace. But the consequences of the Jaula Blanca experiments are far from being extinct, as Koku soon discovers when his supposedly dead lab mate Kirisame suddenly shows up. (Source: Official Site)