Years after the original Kamen Riders' era, a man named Kadowaki Jun was meant to be the first Kamen Rider before the iconic duo emerged. However, his destiny took a different turn as Shocker's thwarted plans left him buried and forgotten for three decades. Awakening in a modern world devoid of his memories, Kadowaki embarks on a journey to unravel his past and uncover the enigma behind his cyborg transformation.