EXE is a street gang comprised of teenagers who hope to become the successors of Museum in Gaia Memory distribution and the antagonists of the final episode of Kamen Rider W.
Seeking to become the new Gaia Memory business, EXE began buying up Gaia Memories as well as taking Yui Aoyama hostage after discovering she held a Gaia Memory. When Shotaro Hidari came across them holding Yui captive while investigating her disappearance, one of their members transformed into the Anomalocaris Dopant to fight him, but was defeated by him as Kamen Rider Joker.
With assistance from Philip, Shotaro is able to apprehend the members of the gang, including their supposed leader Shiro Endo. However, Energy then reveals to the two that he is the true leader of EXE and transforms into the Energy Dopant to fight them. He was eventually defeated by Kamen Rider Double's Joker Extreme Maximum Drive.