is a Japanese tokusatsu series that serves as the 27th installment in the Kamen Rider franchise and the 18th entry in the Heisei era. The series centers on a conflict between humans and Bugsters, a form of computer virus that infects humans playing Genm Corporation (Genm Corp.) video games. Genm Corp. and the Ministry of Health counter the threat by developing Gamer Drivers and Rider Gashats for doctors to save their patients from the Bugster Viruses.
Main characters
Emu Hojo
, also known by his gaming tag of , is a master gamer and pediatrics intern, later surgical intern, who had been inspired to become both after receiving a life-saving surgery and a WonderSwan handheld console from Kyotaro Hinata. Emu is well-meaning and friendly, but also clumsy and absent-minded, which often gets him into trouble with nurses. As the series progresses, however, he matures and becomes less naive, picks up Kiriya Kujo's lying habit, and becomes a master manipulator comparable to Kuroto and Masamune Dan.
Sixteen years prior to the series, the antisocial Emu had found solace in designing game characters. After sending his concepts to Genm Corp. game designer, Kuroto, Emu received a prototype game that infected him with and turned him into patient zero for the Bugster Virus. As a result, an alternate persona called Parad manifested from Emu's desire for a playmate and assumed control, leading to the latter becoming "M" and being kidnapped by Next Genome scientists who had sought to extract the Bugster Virus for Kuroto. However, Parad had turned into a Bugster and separated himself from Emu, allowing the latter to pursue his desire to become a doctor and earn an internship at Seito University Hospital. Despite being separated from Parad, trace amounts of the Bugster's data causes Emu to maintain his gamer persona, become a Kamen Rider, and later grant him the ability to create Gashats from his imagination. After being recruited by CR, Emu has several encounters with Parad, discovers what had happened to him, and joins forces with Parad and other Gamer Riders to defeat the Bugsters and Masamune.
Utilizing the Gamer Driver in conjunction with the platform game-themed Gashat, Emu can transform into Kamen Rider Ex-Aid Level 1. In this form, he gains increased agility and can transform further into Action Gamer Level 2. In both forms, he wields the , which can switch between and . Additionally, activating Mighty Action X generates a digital field and several medals with unique power-ups randomly hidden inside chocolate block-like containers that he can use for increased traversal capability. Moreover, he can combine Mighty Action X with additional Gashats to achieve stronger forms, which are as follows: : A form accessed from Mighty Action X and the beat 'em up-themed Gashat that equips him with the gauntlet. : A form accessed from Mighty Action X and the multiplayer game-themed Gashat along with one to three other Gamer Riders that equips him with the headgear and the extendable . : A stronger variant form that equips him with the Drago Knight Blade and Gun along with his original weapons. Sports Action Gamer Level 3: A form accessed from Mighty Action X and Kuroto's Shakariki Sports Gashat that arms him with the Trick Flywheels. : A form accessed from Mighty Action X and the cooking video game-themed Gashat that equips him with the roller skate-like sabatons and the arm-mounted and condiment bottles. : A form accessed from Mighty Action X and the Pac-Man-themed Gashat that equips him with the gauntlets. This form appears exclusively in the web-exclusive special Kamen Rider Genm: Legend Gamer Stage. : A hybrid form accessed from Mighty Action X and the Gashat that grants superhuman speed, and arms him with the Front and Rear Armed Units. This form appears exclusively in the Kamen Rider Lazer Hyper Battle DVD.