While a member of the Monster Makers in the mid-80's, he is seen by the other members in the group to be rather introverted and visionary in his views concerning the project. He envisions the project to be a stepping stone towards the creation of a Digital World, inhabited with intelligent lifeforms.
The project was shut down in 1986 by Palo Alto University after the Japanese company that funded the project pulled its resources. In 1993, Shibumi continued his own research and development for the expansion of the Digimon programs. However, he is sent into a semi-comatose state after a traffic accident. His awareness, on the other hand, ended up in the Digital World.
He sent a Mokumon was sent to Earth, where it assumed Shibumi’s form, and carried out activities there. The DigiGnomes – early digital lifeforms – had found another use for Shibumi’s algorithm – sending it to the real world via Digimon game cards, creating Blue Cards, it was used to connect humans with Digimon partners, leading to the formation of the Digimon Tamers.
The Mokumon/Shibumi’s made itself known when it transplated a Digimon game card, already containing Shibumi’s evolution algorithm, into the collection of a young games player. The card eventually found it’s way into the hands of Henry Wong, son of Janyu Wong, one of Shibumi’s old Monster Maker partners. Janyu recognised Shibumi’s coding within the card, and, after Henry and the other Tamers failed to track down the card’s source, told his son about his past with the Monster Makers.
He is found by Takato, Henry and Terriermon sleeping in a library in the 5th level of the Digital World; when he is woken up, he explains the architecture of the Digital World, and why the Tamers are designated for their purpose.
Later, he appears in the same form when the Digimon Sovereign are explaining the current threat to the DigiDestined. However, before he fully explains the creation of the D-Reaper and the history behind it, he vanishes, while his semi-comatose body unexpectedly wakes up in the hospital bed in which he has laid for over a decade.
He finally appears in his actual bodily form during the Physical World's fight against the D-Reaper, and re-unites with the rest of the Monster Makers. He created a "red card" for the Tamers to use so when they Biomerge, the Chaos mass where the D-Reaper resided, could not separate them from their partners. Unfortunately, he forgot to account for the Biomerged forms of the children and Digimon together inside the D-Reaper during the "Doodlebug" activation, which wore off just as the D-Reaper was being reduced to its simple program.
He continues to help the Monster Makers, Hypnos, and the tamers over the years, as well as helping other countries set up their own versions of Hypnos. His Mokumon later helps Henry find and rescue the captured Monster Makers during Book Seven.