Chen Yan, a 32-year-old game planner, lives a two-point and one-line life. His only solace is the Kamen Rider figure hidden in the drawer and the vague words of his grandfather when he was a child: "The belt can protect the world." Until the broken belt left behind by his grandfather was accidentally activated, he was involved in a "gap crisis" that spanned multiple Kamen Rider worldviews - the Gurungi in the Kuuga world was polluted by the gray fog, the knights in the Ryuki mirror world were reduced to puppets, and Ofirno in the 555 world accelerated alienation. The originally independent world collapsed due to the collision of unknown forces. Ordinary people would be swallowed by the "gap mist", and the power of the knight became the only salvation.
Chen Yan's belt is not an ordinary transformation device, but a "boundary gap mediator" that can travel through the world, but it also deeply binds him to the "source of erosion": every transformation will increase the risk of his own alienation, and every time he saves one world, it may cause the collapse of another world. He was forced to learn to restrain his strength in the world of Kuuga, face the moral dilemma of "killing or not to kill" in the world of dragon knights, accept the despair of "efforts may be in vain" in the world of swords, and confront the extreme concept of "destruction for salvation" in the world of emperor knights... From a social animal who evaded battle, to a "gap walker" who can stand side by side with the Chief of Tiandao and guide the entire knight alliance, he is always struggling between "protection" and "price".
As the journey progresses, my grandfather's past gradually emerges: he was a Smart Brain researcher, a sound attack apprentice, a core guardian of the gap, and the creator of the Imperial Cavalry Belt. His unfinished "Balance Plan" is the key to solving the crisis.
