Janyu Wong is the father of Henry and Suzie Wong. In his youth, as a student at Palo Alto University, Janyu joined Rob McCoy and a group of other students in an experiment to create artificial life. The group named themselves the Monster Makers, and they all took on codenames, with Janyu being dubbed “Tao.” The group’s experiment resulted in success when they created what would become Digimon, but abruptly was cut short when their funding was pulled, and the experiment frozen. Unbeknownst to them, however, their digital creations accidentally found their way into the Digital World, a parallel reality created by Earth’s interlinked electronics network, where they continued to grow and evolve.
Janyu and the Monster Makers received no credit for the creation of Digimon when a video game, card game and television series were created, but Janyu seemed to take it in his stride and accept the situation, going so far as to buy the latest version of the game for his son.
But Janyu could not escape the past, and soon found himself visited by a mysterious man in black, an agent of the Hypnos organisation, who warned him that there was someone who had not stopped working on the project. He vanished before Janyu could question him.
Knowing that his father had something to do with Digimon, Henry came to him for help when he discovered one of the strange Blue Cards. Janyu scanned its data, and was shocked to discover that it contained code that bore the signature of Shibumi, one of his former Monster Maker partners. He hid the fact from Henry, but the next day, found himself forced to reveal it after making another jarring discovery – that Digimon had come to exist in the real world. Accidentally running across his son, Takato, Terriermon and Impmon in the park, Janyu’s arm was scorched by one of Impmon’s fireballs, and Henry fled before his father could do or say anything. In the evening, Janyu fully explained to him his involvement with the origins of Digimon.
When Janyu found that his place of work had relocated him to the Tokyo Metropolitan Government Building, he was fairly nonplussed, but when he arrived for work, he was left sitting alone in a conference room for hours. Eventually, he was approached by Mitsuo Yamaki, creator of the Hypnos organisation, and taken to its hub, where the system and the process by which Digimon were appearing on Earth were explained to him. All the other Monster Makers, bar Shibumi, had also been gathered there, in order for Yamaki to learn more about Digimon, so he could increase his chances of destroying them. The horrified group also bore witness to the Tamers’ battle with Indramon at this time.
Janyu and the Monster Makers continued their work, only momentarily fazed by some small earthquakes – which, it turned out, preceded the Bio-Emergence of the pig Deva, Vikaralamon. Janyu opposed Yamaki’s activation of the Juggernaut to destroy the Deva, knowing that it would destroy the Tamers’ Digimon too. He swiftly overpowered the security guards with his martial arts knowledge, and headed for the battle site to help the Tamers’, trying to get them to a safe place. Makuramon deactivated the Juggernaut, leading to WarGrowlmon’s destruction of Vikaralamon, but Makuramon then captured Calumon and escaped into the Digital World.
Janyu’s interest in studying Henry’s D-Power, realising how like the Monster Makers’ original portable designs it was, prevented Henry from telling his father that the Tamers were planning on going after Makuramon, and in the end, he learned through an e-mail his son had sent him. Yamaki, turned at last to the side of reason, gave the Tamers a communication device before they left, which they were later able to use to re-establish contact with Earth. Yamaki contacted Janyu and the Monster Makers, and they gathered everyone’s parents together to explain the situation to them – except for Mayumi, Janyu’s wife, who he deliberately hid the truth from. During the meeting, they received another communiqué from Takato and Henry, who had become trapped in an underwater cave. Janyu validated Henry’s idea that in the Digital World, all they needed to do was believe that they could breath underwater, and they were able to escape.
When Janyu took Suzie to the park to play, they encountered Yamaki, and while the two men talked, Suzie fond herself pulled into the Digital World. Janyu also hid this fact from his wife, telling her that she had gone to stay with his father in Hong Kong, but Mayumi saw through the deception, and demanded to know the truth. Janyu regretfully informed her that he could not tell her yet, and was forced to leave to go to Hypnos when destructive energy waves began emanating from the Digital World due to the appearance of Megidramon there.
Subsequently, the Monster Makers began construction of an ark to bring the Tamers back to the real world, utilising, as Janyu explained to Riley, the core code from their Digimon program to make it function. An attack on the Hypnos processor by the true foe of Digimon and human alike, the deadly D-Reaper, almost foiled their plans, but they were able to harness the processing power of computers all across the planet to succeed. The ark Bio-Emerged in Shinjuku Park, but the Tamers soon discovered they had been followed by the D-Reaper, which immediately infested the Shinjuku area, forcing the Hypnos crew and the Monster Makers to pull out of the towers, and operate out of one of the organisation’s vans. Janyu spoke to Henry and his sensei over the phone. Later, the group set up a new temporary headquarters, where Shibumi rejoined the team, and where Janyu received data on the original version of the D-Reaper program from a colleague in Germany. When the Tamers and their families all gathered at the temporary headquarters, Janyu and Tally showed Kenta and Kazu the original D-Reaper program, and then Suzie told Janyu how she had seen Calumon and Beelzemon vanish inside the D-Reaper’s chaos during an earlier battle. An analysis of that area led to the revelation that Jeri was being held within the Kernel Sphere, but after the rescue attempt failed, the D-Reaper evolved into the Mother D-Reaper, forcing the entire group to withdraw to Tsukuba to formulate a new plan of attack. The plan was finalised over the following week, but Janyu kept its details a secret from Henry – pretending merely to be scanning Terriermon, Janyu was, in actuality, uploading the Juggernaut program into him. He feared that his son would never forgive him, but proceeded, seeing it as the only way to claim what would be a pyrrhic victory. When the Biomerged Digimon entered the D-Reaper’s chaos for the final battle, Janyu, Dolphin and Yamaki instructed Henry and Terriermon, as MegaGargomon, to enter the portal the D-Reaper had opened between Earth and the Digital World, and to activate the Juggernaut, reversing the rotation of the vortex. This action destabilised the D-Reaper’s quantum bubble, sucking it through the vortex, which devolved it into its original, harmless state.
However, there was a sacrifice to be made – the effects of the Juggernaut were also felt on the Tamers’ Digimon, who reverted to their In-Training forms and were pulled back into the Digital World as well. As a tearful Janyu tried to explain to his son that it was the only way, and that it would get better, in time, all Henry could do was shake his head, causing the man to fall to his knees and start weeping.
In time, the relationship between father and son began to improve once more, especially once Henry regained his partner. Janyu continued to help both Hypnos and his family in any way he could. He spends quite a bit of time with his old Monster Maker friends, working on one project or another.
In Book Seven, he is captured and taken hostage because of the accusation that Sakuyamon murdered the Prime Minister. Henry managed to rescue him from the truck he was trapped inside and escaped to the park. Though Rayleigh Thompson prepared a trap for the entire group of tamers, digimon, friends, and family that made it there, they still managed to flee to the Digital World. Once there, Janyu was among those who tried to use their limited sources of technology to hack back into the Hypnos computer systems, but failed.