Sasaki is a student who begs Segawa not to fail him because doing so could derail his future as a news anchor. He later pressures Nao to seduce and record Segawa, showing no remorse after the recording ruins Segawa's reputation. Years later, Sasaki works as an editor, is estranged from Nao, and says he is getting married.
Chaotic ally who helps Kuroto distract Fuma. He enters the VR world to restrain Maxima through a mutual sacrifice with Kuroto. In the post-credits, he confronts Bugsters before being intercepted by Kamen Rider Build, who extracts Ex-Aid's essence from Emu.
A mysterious Bugster leader and Emu's direct counterpart who partners with Graphite to spread the virus. He transforms into Kamen Rider Para-DX after completing Kamen Rider Chronicle and aims to eradicate humanity through the game.
Bugster from a parallel world seeking Build's essence, later becomes an ally.
Mysterious Bugster rider with amnesia, later revealed as a dark counterpart to Emu.
Shouma Kai has 21 screen credits in a career dating back to 2008. Their work spans 2 cinematic universes — most prominently Kamen Rider Ex-Aid Trilogy: Another Ending with 2 titles. Signature works include Kamen Rider Ex-Aid Trilogy: Another Ending - Kamen Rider Para-DX with Poppy, Kamen Rider Ex-Aid [Tricks]: Kamen Rider Para-DX, Kamen Rider Ex-Aid [Tricks]: Kamen Rider Genm. Explore the interactive character relationship maps on each title page to trace how their roles connect across franchises.
Universe traveler — spans 2 universes
![Kamen Rider Ex-Aid [Tricks]: Kamen Rider Para-DX (2017) - Shouma Kai Credit Poster](https://image.tmdb.org/t/p/original/4Zz7qKJX05jjVrnA1J9TMi5GUkj.jpg)
![Kamen Rider Ex-Aid [Tricks]: Kamen Rider Genm (2017) - Shouma Kai Credit Poster](https://image.tmdb.org/t/p/original/g4CqdWchP7muPvln0wcHxjHlRHh.jpg)
