The criminal Kaiza Akuma is thrust into the fight against a group of Demons called the Sinful Seven, being brought the Heaven's Access Driver from a childhood friend, Kaiza is someone able to turn it into the Hell's Access Driver, to become Kamen Rider Diavolo. Now stuck in this fight against the Sinful Seven, mysteries start to come up about Kaiza's past and his connection to the demons. Kaiza now much band together with many unique allies as he begins his destiny.