Not having the courage to love, Toru became an adult. One day, he meets his and old friend who happens to find a poem which changes will his fate. This will make Toru gain enough courage to face love once again. He meets a girl Nagi who is bond into his fate, though she has a particular secret
The Game World launches an attack on the Real World. In front of Kamen Rider Ex-Aid and Uchu Sentai Kyuranger appears the "Arena of Death" where the destruction of the Earth will be decided. Trapped in this inescapable dimension, generations of Super Sentai and Kamen Riders must engage in a Battle Royale. An unprecedented battlefield of many puzzles connecting the Real and Game worlds. And then, "Those Heroes" revive... Everything is scaled up, all rules are broken! And when it seems like the real world will fall into a disaster, imagination brings forth unimaginable New Heroes!
A group of revived beast-themed Riders gather to form the "Beast Rider Squad"... and Kamen Rider Ouja, the worst villain Rider, is leading them! Can Kamen Rider Brave hunt them with his new Gashat, "Knight of Safari"? And what is the secret behind this battle?