EXE is a gang that starts causing trouble in Futo a year after the dissolution of the Museum. They claim to be the successors to the Museum's Gaia Memory business, and look throughout Futo for any Gaia Memories that remain.
Shiro Endo is a figurehead leader for EXE who possesses the Edge Memory. He pursues Yui's brother Akira to acquire the Ocean Memory. However, Shiro's posse are defeated and his Gaia Memory destroyed by Kamen Rider Joker before he could use it to transform into a Dopant.
A nameless pet shop employee working under Santa-chan, who goes by the alias of "Energy", is the true leader of EXE. It is only after the members of his group are arrested that Energy reveals himself as he attempts to kill Shotaro for meddling in his affairs. As the Energy Dopant, he is able to fire blasts of electromagnetic energy as well as use his left arm like a rail gun. He is defeated when Philip returns and joins with Shotaro to become Kamen Rider Double CycloneJoker once more, destroying the Energy Memory through the Joker Extreme Maximum Drive.
In addition to Shiro Endo and "Energy", there are three other unnamed members of EXE who fight Shotaro. One transforms into the Anomalocaris Dopant, another transforms into the Cockroach Dopant, and another is supposed to be given the Ocean Memory but never transforms into a Dopant as the Ocean Memory is destroyed before he can use it.