Akane Egusa is a middle school girl selected by Saeko Sonozaki to test the limits of one of the newest Gaia Memories: the Bird Memory. In addition to the fact that no one under the age of 20 is allowed to use a Gaia Memory (a role Kirihiko steadfastly adheres to), the Bird Memory can also be used by those without a Living Connector and it has an addictive side effect.
When Akane runs away from home, her friend Touma Fujikawa is the first to test the true powers of the Bird Memory out and decides to use it for fun with friends Yuichi Kanamura and Yayoi Kubota until Touma decides to use it to attack people as the Bird Dopant. They are stopped by Kamen Rider Double, and the two boys are taken into the hospital after suffering from some of the negative side effects of using a Gaia Memory without a Living Connector.Later, Akane is overpowered by withdrawal from the Bird Memory and attacks Philip who gets in her way of obtaining it. Consumed completely by the Gaia Memory, Akane is able to access the Bird Dopant's Strengthened Form, only to be defeated after the Nasca Dopant assists Kamen Rider Double in finding the Bird Dopant's weak spot for a direct strike on the Bird Memory by means of CycloneTrigger's Trigger Bat Shooting Maximum Drive.