Here is an overview of the game, via its official website:

Story

• A Completely New, Original Story – A completely new, original story set in the world of Cardfight!! Vanguard overDress will unfold. Featuring characters drafted by Cardfight!! Vanguard co-creator Akira Ito.
• Cardfight!! Vanguard overDress Characters Also Appear – Yu-yu Kondo (voiced by Shouta Aoi), Danji Momoyama (voiced by Yuuki Ono), Tohya Ebata (voiced by Yuuma Uchida), and more characters from Cardfight!! Vanguard overDress also appear in the story.

Characters

• Yuki Ichidoji (voiced by Yuka Nishio) – A second-year high school student at Omi Academy. She is a strong-willed and honest girl who excels in both academics and athletics. After tailing her brother one day, she stumbles into the world of Vanguard.
• Rasen Ichidoji – A third-year middle school student at Omi Academy. Usually quiet, his personality is the polar opposite of his older sister’s. However, he possesses an unwavering heart and is awakening to his potential as a Vanguard player.
• Gosetsu Katsushika – Owner of the paper talisman shop Sakura Ogi. His care for others and passion for Vanguard has made his store a hotspot. He once led the largest team in the area.
• Kanji Meguro – President of the national retail chain Berserk. With his overwhelming charisma, everyone around him constantly showers him with praise.