Ultraman: I am really just a human.

Xia Chuan accidentally travels to an alternative Ultraman universe similar to the world of "New Ultraman" and becomes Shinji Kaminaga, who has just separated from New Ultraman.
However, as the former human host of Ultraman, Natsukawa was surprised to find that he had become an outcast of the times.
Five years have passed, and Ultraman has been forgotten by humanity. The Kamen Rider era has begun. Natsukawa, who possesses the Ultraman fighting evolution system, not only loses his hope of becoming a life form of light because of Zoffy, but his application for Kamen Rider qualification is also repeatedly thwarted...
This is the story of a washed-up hero seeking a path to super evolution in a dark universe.