It has been seven years since Sei Iori won the 7th Gunpla Battle Championship World Tournament. Gunpla Battle is now more popular than ever, with new rules and new ways to battle. Fumina Hoshino is the president of the Gunpla Battle Club at Sei's old school, Seiho Academy, and a big fan of the game, but unfortunately, she cannot attend the upcoming All-Japan Gunpla Battle Championship tournament without a three-person team. Desperate to participate, she meets transfer student and young martial artist Sekai Kamiki, as well as a young Gunpla builder named Yūma Kōsaka...