The Riders make their final assault against the ever-growing Jyamato, hoping to discover the secrets of their existence and return peace to the world.

早乙女家的家庭聚会映像在流出一周后，新堂一叶的女儿梨里杏留下了神秘讯息便丢了性命，甚至还被捏造出了“和班主任爸爸活”的丑闻，受到社会的批判。失意的新堂一家为了探寻女儿去世的真相，潜入早乙女家实施复仇……

The "Desire Grand Prix" is a game to protect the peace of the city from the threat of the mysterious enemy "Jyamato", whose origin and purpose are unknown. Each participant transforms into a Kamen Rider and competes to win the game by defeating enemies and saving people. The winner of the Desire Grand Prix will be rewarded with "the right to bring an ideal world to life" as a prize. In other words, only the true heroes who win the competition will be able to realize the world they have wished for.

在黑心电视节目制作公司拼命工作的社畜女主・27岁的鹿森海（铃木爱理饰），在每日繁忙的工作中，渐渐忘记自己的梦想，忘记恋爱的感觉，变成了“找不到幸福的颓废女”。而在一次偶然的采访工作中，遇到了比自己小却傲慢自大的摄影师・长岭风绪（本田响矢饰）和不会谈恋爱的年上社长・榊圭祐（白洲迅饰）。

这次相遇，给海带来了跳槽进入“ANIMAL BEAUTY”公司的绝好机会。她将如何在这里实现自我的华丽蜕变，并在弱肉强食的严苛环境下出色完成工作，抓住自己的幸福呢？