Hey, that man beside Shinji at 2:39 is actually the Original Suit Actor for Ryuki. His name is Takaiwa Seiji. He aka as Mr.Heisei Rider, because he is the suit actor for all the primary riders in Heisei era (except Kuuga and Hibiki).
I wonder what happened to Yui and Shirou for the Kido died ending. Ren survives and he wishes for a world without the Rider fights and no mirror world and monsters but then the camera pents to a couple of photo of Shirou and Yui when they were kids.
Yes, the actor that played the character Shinji Kido in Kamen rider Zi-O and spinoff Rider Time Ryuki is without a doubt, his original actor Takamasa Suga.