Becoming Kamen Rider Ex-Aid, Emu now must serve as both a pediatrician and a member of CR. A gifted surgeon named Hiiro Kagami comes back from the United States and is not only the son of the director, he’s also Kamen Rider Brave. This results in a clash of ethics when it comes to dealing with patients.

Unable to control the powers of the new "Drago Knight Hunter Z" Gashat only by himself, Emu discovers that to do so he must convince the other Kamen Riders into join forces with him. Once he tricks them into doing so, the time comes for their showdown with Graphite.

Ex-Aid, now as two, get into an argument about defeating Genm or the Aranbura Bugster. They both seem to be Emu, but Genm and the Bugster take this opportunity to escape. Emu reverts to his human form and falls unconscious.

Wanting to save Dr. Shirakawa, Emu asks Hiiro to perform a surgery on his cancer. He has his Gashat back and faces the Aranbura Bugster to also cure Shirakawa's game illness. Will the surgery succeed? What will happen to Ex-Aid?!