I'm really just human

Natsukawa accidentally traveled through an alternative Ultra universe similar to the world of "Ultraman New" and became Shinji Kaminaga who had just separated from Ultraman New.
However, as a former Ultraman in human form, Xia Chuan was surprised to find that he had become an outcast of the times.
Five years have passed, Ultraman has been forgotten by mankind, and the Kamen Rider Era has arrived. Natsukawa, who has no Ultraman Fighting Evolution System, not only loses the hope of becoming a life form of light because of Zuo Fei, but his application for Kamen Rider qualifications is also frequently blocked...
This is the story of a has-been hero seeking the path to super evolution in a dark universe.