Emu developed interests in video games at the mere age of 8, which he proved to have a natural talent for in the near future. This lead him to creating the concept for Mighty Brothers XX, to ease his loneliness. From a young age, he was a huge fan of Genm Corp. and often sent fan letters to one of its programmers, Kuroto Dan, which had included ideas for new games. Furious that someone who could create game concepts on par with him, Kuroto sent Mighty Action C, a game in-development which, unknown to anyone but Kuroto, had been infected with a strain of the Bugster Virus, which subsequently infected the boy.
On one rainy day, Emu succumbed to the Bugster Virus and subsequently got involved in a traffic accident. After receiving an emergency surgery from Kyotaro Hinata, Emu was given a WonderSwan handheld video game device by Dr. Hinata as a reward for hanging on. This event would inspire Emu to become a doctor and help children like the one who saved him.
Emu would later go on to win numerous gaming tournaments under the gaming alias of M. Sometime in 2010, Emu trained vigorously for a gaming tournament he had participated in, at the cost of his health. Unknown to him, Kuroto watched his victory in the shadows, having watched Emu for a decade. Shortly after, Emu was abducted by the Next Genome Institute, who had been hired by Kuroto to remove the now-mature Bugster Virus from Emu's body. After the matured Bugster later known as Parado was successfully removed from Emu's body, the members of the Next Genome Institute vanished. Emu would believe that the operation was nothing more than a dream. Following the incident, he decided to take a serious attitude in his entrance exam and pursue being a doctor. However, the leftover Bugster Virus in his body would create a split personality that represented his gaming interest. The Bugster Virus that had been extracted would be used as the basis for the virus used for Zero Day a year later.
It seemed to be pure chance that Emu had become Ex-Aid to begin with, considering everything else that's happened. What would've been a simple check-up on one of his patients would spiral out into his first contact with the Bugsters proper, not only with the hybrid Lexx but also with the main boss of Mighty Action X, Salty taking form. Seeing a chance to take action with a corrsponding Gashat and Driver, he becomes Kamen Rider Ex-Aid to take on Salty with Lexx, and defeat the enemy Bugster.
"However, whatever relief with becoming part of CR proper would soon fade with having to deal with the imminent onset of Bugsters, while also having to deal with another such Rider, Hiiro Kagami, AKA Kamen Rider Brave. Things would also change for the worse when the new Bugster, Aranbura absolutely wipes the floor with him, leaving him unable to continue being a Rider until he could get his act together again.
It would only get more complicated from there, as in his brief limbo period he is given a chance by a mysterious stranger to continue being a Rider with a different Driver and Gashat, as the opportunity to continue being Ex-Aid to deal with Revol. He chooses the latter, but tells the stranger to entrust the gear to Asuna Karino and let her be a Rider too as he comes back into the fray to try and do what he does best.
From there he also tries his best actively deal with the crisis at hand, as he and the rest of CR are informed of the theft of some of Genm's additional Gashats, as well of an old rival of his resurfacing to take revenge; Nico Saiba, who had taken the Gekitotsu Robots Gashats to settle such a score with him as the Collabros Bugsters are let loose to take the Bugsters' fight directly to the Riders. The rivals got their match, but end up with Nico becoming a cyborg from her own recklessness, leaving the poor doctor and an ever-present Lexx lost on how to fix the hybrid.
After much prodding and desperation however, the two are picked up by the mysterious stranger and his odd assortment of animal-themed train cars, since there seemed to be no way of treating Nico and her newfound Bugster Hybrid status under normal cirmustances. It's there he learns two very important things; Who this stranger actually is, a time-displaced ranger named Nikolai Blecker and their current mission, to stop the game known as Power Rider Go! from claiming any lives as part of its everyone-for-themselves gameplay.
This is a lot to take in for a newly-minted rider only used to taking on Bugsters at this point, especially moreso with the discovery of Bugster Hybrids like Lexx and Nico along with Power Rider Go! and how its Power Players are automatically at Level X, a level none of the Riders are anywhere near, so Emu and Blecker start working together to sort Level X out with help from a certain Wendall King, who serves as a liaision between CR and Machina Vision and already possessing the Level X Monster Safari Gashat.
At this point, Emu hypothesised that being inoculated with a viral strain for what he thinks has been 6 years up to this point would give him a greater resistance to any viral backlash created by the Gashat, but would be proven wrong as it creates a Bugster Rival intent on assimilating him instead. It was only due to Hiiro and his aides severing their connection that Emu was able to safely transform and try to deal with the rival, only for both sides to withdraw thanks to a spot of really bad luck.
After than incident, he has an odd idea for his own Level X Gashat, which would then have a basis in the even more theoretical Level i: A hack and slash Gashat themed after Magical Girls and centered around a viral purging ability, thinking it'd be a way of curing unwilling hybrids like Lexx and Nico. Seeing a chance to get him introduced to the grand scope of the situation, Blecker humors him on the idea and asks if he would like to meet one of those Magical Girls in person. He agrees, thinking it would help him with figuring out how the Gashat could work.
The two then would end up in Equestria, a magical place populated by animals ponies and other magic creatures, a perfect place for help on figuring it out. However, it's nature would lead to some complications that would become apparent the longer they stayed there thanks to some advantageous time dilation, including Lexx going feral and starting to turn the whole of Ponyville into tigers like her. Whatever attempts at getting her to snap out of it don't take at first and she flees into Everfree Forest into the company of a pack of Timberwolves.
After some additional convincing, including fighting said Timberwolves, Emu and Blecker, but mostly Emu are able to convince Lexx to realise what she's done and get to work trying to resolve the situation, while also finishing the Level i Gashat in question at the same time. While all this was happening, Nico had gone feral, infected Navi and took off with one of the train cars back to Earth.
With something like Lexx's rampage possibly repeating on Earth, everybody just starts working on the Gashat as quickly as they can, because while the dilation is advantageous to them, there's still only so much time they can spare before they absolutely have to go back. Realising this, Emu also makes plans to head back to Earth early to deal with the situation before she could infect somebody and it gets out of hand, hopefully.
Of course, Emu manages to get back after a detour in America and introduction to Power Rider Go's real scope but not without a slight change only Saki had noticed at first; He had become a woman who goes by 'Mima Hojo', who according to the still-slightly feral Nico is Emu's sister, which is true to a certain extent. The reunion, in hopes of getting Nico to open up about herself goes awry when Nico leads her to a pride of cat girls obsessed with hunting others with thought for little else as the pride tries making Mima one of them.
It would go further awry as immediately Mima establishes herself as leader of the pride due to her skills, they are all picked up by Souichi Isurugi, claiming to be a friend of Blecker's when he was in reality the extradimensional terrorist Blood Stalk, or Evolt as he'd also been known as. They would all be never to be seen again, except Saki runs into two catgirls working for the terrorist organisation Faust, who claim to not be Emu and Nico but otherwise look identical to how she last saw them. The attempt by her to save them does not take, and they leave her devestated with no adequate way of explaining who Faust and Evolt are.
Mima, or Nyan as she's called herself would sporadically make appearances since then, trying to gather data for Faust and attempting to reposess their hardware while turning heads all around as part of a growing population of catgirls. That is, until Kamen Rider Odin, doing a favour for Saki finds the two brainwashed operatives and not only tries appealing to their former identities but also lures them near something reflective to bring them back to CR so they could be un-brainwashed.
The attempt was a total success this time, but for whatever reason Emu had not been brought back so much as Mima had been such, knowing all of what Emu knew through the lens of another witness like a relative. It still works however as a win for CR through having the Emu remnant that was planted by Faust to throw them off CR's scent, and one willing to pick up right where the original left off. With the 'siblings' being able to catch up with Blecker as both Power Rider Go and Kamen Rider Chronicle are up at each others' throats, the three along with a relucant Taiga decide to work together to resolve the situation.
Emu Hojo is a very clumsy and yet a serious doctor to take on his job. However, his thirst for playing video games has a problem of Emu being absent-minded at times. An example of this is he sometimes fails to remember his work schedule properly and it makes the nurses scold him. He also has a habitual quirk of tumbling down in various comical ways.
Name: Mima Hojo
Age: 24
Birthday: [Redacted] 1992
Gender: Female