Episode 0 of Dies Irae.

Straightforward and innocent Hisone Amakasu is a Self-Defense Force rookie stationed at the Air Self-Defense Force's Gifu Base. She was struggling with the fact that she sometimes hurts people unintentionally by her innocent words and decided to join the Air Self-Defense Force, hoping to maintain a certain distance from people. This decision led her to a fateful encounter which profoundly changed her life. It was the "OTF" dragon hidden in the base and it chose Hisone as his pilot. When it soared into the sky with Hisone, her fate as a dragon pilot was decided. It is said that dragons have a key to the future of the world... (Source: ANN)

After two years of studying within the Reiken clan, Ouriku and other inexperienced disciples are ordered to descend to the temporal world for further studies, and Ouriku embarks the journey back to his birthplace. (Source: ANN)

Four months after the battle at Nagoya Castle, Yu-yu and friends received an invitation to a tournament. That "Deluxe" tournament aims to determine the strongest fighter, bringing together both "Front Fighters" who are active in official tournaments, and hidden powerhouse "Counter Fighters" like "Blackout" that compete against each other for flags. The existing characters from overDress will be competing with new characters from will+Dress such as Raika, Michiru, and Urara, to become the strongest of them all!