Mr. Mizuno, a.k.a. Shibumi, is one of the Monster Makers, and the one most directly responsible for creating Digimon.
Voiced by Bob Glouberman
When the Monster Makers worked on the Digimon project and it was shut down, Shibumi continued it and successfully finished creating the digital world and Digimon.
Shibumi bumped into the 7 kid causing him to drop his cards, leaving a blue card with him (an algorithm that enables bio-emergence and matrix digivolution). Janyu scanned the card and noticed his code. The card later digivolved Terriermon to Rapidmon during the fight with Pajiramon.
Shibumi was connected to the digital world through a machine, appearing in the digital world in a transparent form. Eventually Takato, Henry, and Terriermon found him and he explained many things about the digital world to them, as well as the creation of Guilmon and Terriermon. He also provided them with an ark to travel through the digital world.
Shibumi later arrived to tell the tamers, Azulongmon, and Zhuqiaomon the name of the true enemy, the D-Reaper. He described the D-Reaper to them, but before he could say more, he was disconnected from the digital world.
He later rejoined the other Monster Makers to help the tamers fight the D-Reaper.