She was portrayed by the martial artist Chihiro Yamamoto, who later portrayed Laiha Toba in Ultraman Geed.
6 years prior to the beginning of Kamen Rider Ex-Aid, Ageha Takeda and her fellow researchers were conducting an experiment on a patient infected with the Bugster virus to evolve the virus into a new life-form when an accident happened that caused all of the Next Genome Institute researchers to be killed and transported into the Game World, turning them into Bugsters as a result.
In the present day, Ageha Takeda and her comrades escaped the Game World and began working to continue their research. Through an altered version of the Bugster virus they engineered called the Pac-Man virus, the Next Genome Institute began rapidly spreading the Bugster virus in order to locate the strain of a new type of Bugster virus to experiment on.
The Giril Bugster was later destroyed by Kamen Rider Gaim Kiwami Arms.