Emu Houjou (Kamen Rider Ex-Aid)
A pediatrician at Seito University Hospital, and a doctor at the Cyberbrain Critical Care Center (CR). Also known as Genius Gamer M.
He has always loved video games since he was very young, and would imagine having friends to play with.
At the age of eight, he was caught up in a car accident, and Kyoutarou Hinata saved his life and inspired him to become a doctor. He carried on the fight, both as a doctor and as Kamen Rider, so that his patients could smile again. He accepted Parad, the Bugster who had infected him, as a part of his own personality, and the two began working with each other. He is currently treating patients with Game Syndrome, while also working to develop regenerative medicine for those who have disappeared.
Hiiro Kagami (Kamen Rider Brave)
A genius surgeon at Seito University Hospital, and a doctor at the Cyberbrain Critical Care Center.
He lost his girlfriend, Saki Momose, to Game Syndrome, and after getting in repeated conflicts with Taiga Hanaya, who had been involved in her disappearance, the two eventually reconciled. He is now working as a surgeon to save the lives of many patients, hoping to reunite with Saki with the help of regenerative medicine. He has a personal policy of not getting too personally invested in others, and has a habit of referring to people by their title instead of their name.
Taiga Hanaya (Kamen Rider Snipe)
A medical practitioner who specializes in Game Syndrome and runs the Hanaya Game Syndrome Clinic.
He had once been a radiologist at Seito University Hospital, and was the first doctor at the Cyberbrain Critical Care Center to become a Kamen Rider. He was responsible for the disappearance of Saki, a patient with Game Syndrome, and had his medical license confiscated by the Ministry of Health. He held a deep grudge regarding Hiiro and Saki and a deep hatred for Bugsters, but after many struggles, he eventually reconciled with Hiiro. His relationship with the Cyberbrain Critical Care Center has also improved since.
Kiriya Kujou (Kamen Rider Laser)
A doctor at the Cyberbrain Critical Care Center.
He had once worked as a medical examiner with the goal of eradicating the Bugster virus, but Kuroto Dan silenced him for learning too much about his secrets. Afterwards, he revived as a Bugster and started working with the Cyberbrain Critical Care Center to help develop a Game Syndrome vaccine. After a final battle with Kuroto, he became the world’s first case of a human regenerating from a Bugster state.
Poppy Pipopapo (Kamen Rider Poppy)
A Bugster who works at the Cyberbrain Critical Care Center, and the Kamen Riders’ mission control.
She usually provides support for Emu and the others as a nurse named Asuna Karino. She was the Bugster who infected Kuroto’s mother, Sakurako Dan, and to her, Kuroto is both her son and a parent who created her. At one point, she vaccinated herself in order to stop the Gamedeus virus pandemic, but she was revived after being cultivated in Kuroto’s body.
Parad (Kamen Rider Para-DX)
The Bugster who infected Emu.
He was the world’s first Bugster, born from Emu’s desire for “a friend to play games with”, and had worked alongside Kuroto in the shadows. He started off with a hostile relationship with Emu, but after many battles, he learned the importance of life without any continues and the fear of death, and, repenting for his sins, joined Emu in super-cooperative play. He disappeared alongside Gamedeus in order to save humanity, but he was revived after being cultivated in Emu’s body.
A genius pro gamer with an annual income of 100 million yen.
She was defeated by Genius Gamer M at a game tournament, and made her way into Taiga’s clinic in the hopes of defeating M. She became a patient under his charge, and while she continued staying in his clinic for a long while, she was proactive in helping them clear the ultimate game, Kamen Rider Chronicle. She is also a major shareholder of Genm Corporation, and is currently active as a pro gamer in the United States.
Kuroto Dan (Kamen Rider Genm)
A genius game creator, and the culprit behind the tragedy that led to the spread of the Bugster virus.
In the past, he intervened in the fight between the doctors and the Bugsters, both as the CEO of Genm Corporation and as Kamen Rider Genm. Although he was attempting to complete Kamen Rider Chronicle, Parad betrayed him, and he disappeared. Afterwards, Poppy revived him as a Bugster. Calling himself names such as “Kuroto Dan Remastered” and “Master Kuroto Dan”, he was placed under the control of the Ministry of Health, and formed a temporary alliance with Emu and the others in order to retaliate against his father, Masamune Dan, for exploiting his talents. Afterwards, he escaped from imprisonment, and threw the world in to chaos as he continued pursuing his talents and tried to bring about a revolution, but in the process, he used up all 99 of his lives and disappeared.