Mitsuhide Nira, who has been revealed to be the murderer of Eisuke Tomari, takes steps with Brain to hide away the evidence from 12 years ago. Moreover, they hold a press conference, falsely accusing the Special Investigation Unit of colluding with the Roidmudes, landing them in jail and Shinnosuke as the public's most wanted criminal. Shinnosuke must find a way to free the Unit and expose Nira of his crimes.

Nira put the Special Investigations Unit in siege to lure Shinnosuke into a trap. He intends, after framing Shinnosuke for the whole incident, to kill him and make it appear as if it was self-defense with the same gun that killed Shinnosuke’s father, with the other Riders fairing no worse, with Go fighting Heart wanting Banno's tablet, and Chase unable to save a poisoned Yukari with Mad Doctor.