A 14-year-old teenager from Nagoya who willingly signs up with Shinkansen Ultra Evolution Institute Nagoya Branch to be a fully trained Shinkalion Driver, and is by far, effectively the eldest of all under-aged Drivers to be recruited into the institute.
Ryūji is the son of Chikuma Kiyosu, who like Hokuto Hayasugi, is also a core developer of the Shinkalions; making Ryūji of similar background as Hayato. But unlike Hayato, Ryūji was a highly disciplined karate martial artist who had the potential to champion competitions, but dropped out of continuing the art to tend his family due to the death of his father, and hospitalized ill mother. In order to aid his late father's passion for Shinkalions, he voluntarily signs up to be trained as a professional Driver.
- Chikuma Kiyosu (father, deceaced)
- Kaede Kiyosu (mother)
- Tatsumi Kiyosu (younger brother)
- Miyu Kiyosu (younger sister)
- Hokuto Hayasugi (mentor)
- Rindo Hashima (superior)
- Shimakaze Anjō (trainee)
- Nagara Anjō (trainee)
In the series
He shares the same voice actor with his father Chikuma Kiyosu.