This article is about a/an patient/game developer in Kamen Rider Ex-Aid.

Tsukuru Koboshi (小星 作 Koboshi Tsukuru) is a video game developer for Genm Corp., and later its fourth CEO.

Character History

Ju Ju Burger

Tsukuru was one of the developers of the Rider Gashats, which he had worked on for five years along with the rest of Genm Corp. development team for the project.

After the sudden disappearance of his boss Kuroto Dan, Mr. Koboshi tried to keep the company afloat after a lack of leadership caused Genm Corp. to suffer financially by developing a new game: Ju Ju Burger. His fellow employers also support Tsukuru to lead the development team under the new CEO of Genm Corp..

After an exhaustive amount of work, the game was completed. But the game was infected with the Bugster Virus and became corrupted and then infected Tsukuru. The Burgermon Bugster emerged from him, which frightened Mr. Koboshi at first until he realized it was in the likeness of his creation Burgermon. He then embraced his creation and the Bugster became friends with him, looking after him whenever the Game Disease made Mr. Koboshi feel sick. To develop the Ju Ju Burger Gashat, Tsukuru "borrowed" access to Kurto's private terminals to develop the game's coding. He created the game in case he needed to go to the CR to discuss his unique case of Game Disease.

One day, his friend Burgermon went outside and caused a panic because he was hungry. After being chased by Emu, Burgermon met up with Tsukuru who tried to feed him burgers from Ex-Aid Burger Gamer Level 4 to satisfy his hunger. When Ex-Aid talked about destroying Burgermon and Snipe was shooting at the Bugster, Tsukuru became stressed and began fading away. It wasn't until Ex-Aid saved Burgermon that Tsukuru's stress subsided.

However, his happiness did not last long as he witnessed the destruction of Burgermon at the hands of Genm Zombie Gamer Level X, Tsukuru's former boss and the Gashat he created was confiscated by the evil Rider. A Nonstandard BURGSTER?

The Motors Ordeal

While mourning his late-Bugster friend Burgermon, Tsukuru ate a burger to honor his late friend. However, Kuroto sprays Tsukuru with a Bugster Virus from his Bugvisor, causing Tsukuru's to become sick again while manifesting Motors' Level 5 body, as the Bugster plans to eliminate Tsukuru's supporters within Genm Corp. Back in the CR again, he explains that when Kuroto became a fugitive, Genm Corp. is at a critical crisis without a CEO until the new CEO arrived. When Genm used Motors as bait to lure Ex-Aid, and destroy it which completely forge Parado's alliance with Kuroto, Tsukuru awakens and is cured quickly. The Truth Exposed

The New Gashat

Taiga later uses the memory of Burgermon's death by Genm as well as a significant amount of money to recruit Tsukuru into making a Gashat for a game about killing zombies, believing that this will be the key to countering the Dangerous Zombie Gashat.Chasing the Mystery!

Taiga comes back to Genm Corp to see the progress of his new Gashat. While Tsukuru has completed a prototype of the Gashat, he misunderstood the request by aiming for a fighting-monk theme. His idea is quickly shot down by the bewildered Nico and Taiga, who demand the Gashat to reprogram themselves. Tsukuru then lets Hiiro use his computer to utilize the late Kiriya Kujo's data on the Bugsters to program his Gashat. When the Bugsters begin to invade Genm Corp. Tsukuru flees to safety.Engineered History!

Kamen Rider Chronicle, Begins

Though the company seems return to normal however, turns out that Tsukuru's new boss Ren is also evil as Kuroto was since the day when Kuroto was on the run from authorities and had been a Bugster working for Parado all along, unaware to Tsukuru and the other human employees.

After the death of Masamune, Tsukuru was appointed as the new CEO of Genm Corp., and begins collaboration with Kiriya Kujo to work on vaccines for the various strains of the Bugster virus. Endless Game He held this position for at least a year, presumably continuing to remain as CEO ever since. Kamen Rider Ex-Aid: True Ending


Tsukuru is warm and friendly, albeit somewhat timid. He has been shown to be popular among his colleauges for his deameanor and skill.


  • Skilled Programmer: While nowhere near the level of Kuroto Dan, Tsukuru has an excellent proficiency in programming. He completed the JuJu Burger game almost entirely on his own, and is one of three people (Later four) to successfully create a Gashat.

Behind the Scenes


Tsukuru Koboshi is portrayed by Shohei Uno (宇野 祥平 Uno Shōhei)


Tsukuru's first name is the Japanese word for "to create" (作る tsukuru).


  • While not the first Bugster patient to be infected by the Bugsters of two different games, Tsukuru is the first to have been given two infections at two different times, both previous double-infected patients receiving both of their infections at once.
  • Tsukuru is the only CEO of Genm Corp. to never fight against CR.