When he was 14 years old, Kuroto was a developer for his father's company, Genm Corp. Kuroto was extremely talented, due to the fact that many of his games were both bestsellers and masterpieces. During the Y2K problem, he discovered a computer virus, which would be later known as the Bugsters. One day, he received fan mail from Emu Hojo, suggesting ideas for a new game. Impressed, yet angered, Kuroto could not believe that someone else would be as talented as him. Thus, in revenge, he created a game known as Mighty Action C, and sent it to Emu. Emu would play it and be infected with the Bugster Vaccine, spawning Parado in the process.

Some time afterwards, Kuroto had unintentionally infected his mother with the Bugster Virus. Desperate to find a way to save her, he enacted Zero Day, and eventually came up with the idea and purpose of the ultimate game: Kamen Rider Chronicle.

Kuroto had been observing Emu from the shadows for a decade, in order to observe the development of the Bugster Vaccine within the latter. In 2010, after Emu won the Tekken tournament against Nico Saiba, he would soon be abducted by the Next Genome Institute, whom Kuroto had hired to remove the now-mature Bugster virus from Emu's body. Shortly after the operation, the matured Bugster (later became known as Parado) was separated from Emu, while the members of the Next Genome Institute vanished. Kuroto would later use the virus harvested from Emu as the basis to trigger Zero Day.

Kuroto has been CEO of Genm Corp. for at least five years. He was present during the beginning of Zero Day, when the Bugsters emerged from the glitches in ten of the games his company was developing on his desktop. While collaborating with the Ministry of Health, Kuroto helped design the Proto Gashats and Gamer Driver as a countermeasure to the Bugsters, all while managing to keep his agenda for unleashing the first Zero Day hidden from the public eye, by framing his father for this. During Zero Day, Kuroto assigned Taiga Hanaya, who was a radiologist from CR at the time, to become the first Gamer Rider, giving him the Proto Bang Bang Shooting Gashat and also Protosnipe's Gamer Driver. In reality, he was using Taiga as a test subject on finishing the Proto Gashat's finalized counterpart. However, upon Protosnipe's defeat to Graphite due to the Proto Gashat's side effects, Taiga left CR, and left his Gashat and Gamer Driver as well, while Hiiro Kagami becomes Kamen Rider Brave after the death of his girlfriend Saki Momose, who was Graphite's host. During this time, many other casualties were also infected, including Heiji Uesugi's son, leading Heiji to investigate Zero Day for years. Two years later, Kuroto was confronted by Kiriya Kujo, a coroner who had found out about Zero Day after his friend Jungo died in an accident before the virus in him manifested to the real world. Kiriya was given a Gamer Driver and the Bakusou Bike Gashat, in exchange for his silence.

Five years after Zero Day, Genm Corp. had finally completed one of the ten games, Mighty Action X. On the release day, the Salty Bugster emerged from Sota Suyama. The Bugster was defeated by Kamen Rider Ex-Aid and Kamen Rider Lexx. Following Ex-Aid's debut, Kuroto called Poppy Pipopapo and ordered her to record Emu's specs as Ex-Aid, using his specialized VR for later use.

Soon after the incident, Kuroto met with Kyotaro Hinata. Hinata thanked Kuroto for providing the Driver and Gashats. Kuroto responded humbly, before asking how the incident was covered up. Sometime later, Kuroto took up the mantle of Genm to interrupt Ex-Aid and Brave's fight against Aranbura. He attacked the two Riders, allowing the Bugster to escape. After the incident, he was approached by Taiga Hanaya, who had been Protosnipe during Zero Day. After receiving large piles of cash, Kuroto gave Taiga a new Driver, along with the Bang Bang Shooting Gashat.

As the Riders started their fight Kuroto took up Proto Might Action X as the black Ex-Aid Genm to test and train the other riders to face greater threats while also punishing those he felt were undeserving. This included a stint with Ex-Aid and Lexx where he took their gashats and drivers but when Blecker offered new ones to Emu he secretly slid them back. Hew keeps up this ruse for a while until Graphite nearly defeats everyone so he debut's as Kamen Rider Paladin to keep the team alive while still keeping Genm a secret from the others.

As Power Rider Go! Heats up the group, including Paladin Kuroto clash swords with the Female Ex-Aid known as Power Rider Extreme, this Level X rider mops the floor with everyone and kills, in no uncertain terms, Kiro, Kuroto, and Kiyra sending them to Tenkuji Takuru to be judge for the after life. With quick thinking Kuroto convinces the guardian of the dead that his antagonistic actions as Genm were for the benefit of the CR riders, providing them with a challenge to foce them to be prepared for Power Rider Go! Which judging by his own defeat and death wasn’t even close to enough.

Given a second chance at life with a Ghost diver along side Kiro and Kiyra he is given the same ultimatum to find the 15 new eyecons but Kuroto always 3 steps ahead leave Kiro to the quest alone as he studies his new ghostly body as he develops a new gashat to give him a second chance at life on his own terms, Immortal Ghost, though he has to play thing close to his chest with Kiyra every watching him.

When Emu goes missing with Nico into the World of Build a wrench is thrown into Kuroto’s plans for developing his own level X gashat and he is forced to fall back on Lexx’s Player driver and Researching Past Rider to finish Kamen Rider Chronicle as Go! Goes multi national bringing the Rider War to his shores. While Kurot oat first plays off the sacrifice of Lexx to create Evolving Tiger level X as a necessary evil as time goes on he begins to regret loosing his adoptive sister just as he lost his mother all those years ago driving him to seek newer and greater heights of power to prevent loosing another loved one.

With the power, and data of Lexx, in Evolving Tiger Kuroto finds himself stuck for periods of time I nthe body of a catgirl like Lexx which untimely leads, due to the Digimon Code inherited from Lexx to Kuroto being bound to Saki as her tamer and being stuck permanently in the form of a catgirl. Through several rebirths as a Digimon and much training Saki raises Kurto and Lexx to be powerful allies as they fight the never ending Rider War, the return of the Dragon Asami and her near loss to Power Rider Nebula promos Saki to bind Asami as her third Digimon Partner where Kurot discovers that Asami’s power is so massive the digivice can not even calculate it. Seeing an opportunity to grow even stronger Kuroto separates the Digimon code from Evolving Tiger preventing the gashat from transforming even more people and compounding the issues while finding a way to extract the excess dragon data from Asami and then assimilating it into herself gaining the strength of the dragon and the power of X in her base bugster form, but as Kurto would soon learn she was playing with fire.

With her focus now on breaking the cycle of rebirth that comes with Digmon and Finishing Kamen Rider Chronicle Kuroto develops as power up with Drago Knight Hunter XX for Saki but wars it may bring back the threat of Graphite, believing, like many others that Graphite and Saki were 2 separate entities instead of an evolution of one and thus offers up Evolving Tiger as an alternative bur leaves the choice to Saki. Kuroto also extracts the Catgirl Creator code from Evolving Tiger removing another of its side effects and making Evolving Tiger XX the perfected form it was meant to be.

Already stuck as a catgirl however Kuroto uses the new Catgirl Creator XXX to further increase her combat power while hunting with Digimopn Lexx in Monster Safari for food, but the power of the Dragon soon overwhelms Kuroto and she finds herself hunting adventurers and scorching the towns of the world of D&D for more wealth and power and when Chronicle begins she sees out Bugster OOOs Yummies to further increase her horde with the cell medals of growing yummies, even willing to sacrifice a core medal to Power Rider Drive for a mass of Cell medals, always seeking more wealth and power, the dragon had truly taken over.

Finally fed up with Lexx’s nagging to restore her and Asami memories Kuroto restores the two but keeps Lexx’s Ego out of the code seeking to make a better Lexx then the one he grew up with, one without the massive ego of Genius Rider X but all her other memories and skills intact, it was clear that Kuroto was not done playing god just yet.

This comes to a head when Kuroto secretly unlocks Mighty Action Origin and revives an older Bugster copy of herself to play the roll of Genm to keep the riders on their toes, even letting Genm defeat her so she can play up that “Genm attacked her and stole Mighty Action Origin.” Wit hall loose ends tied up Kuroto packed up her horde and lap and moved to a new location not telling Saki, Lexx, or anyone leaving them quite surprised when Lexx Leads Hiiro to Kuroto’s lair to find it empty and with no clues as to where the genius Game Master has absconded to.