Genzo in canonEdit
It has never been stated in canon just when Genzo became aware of Agito, but what is known is that he is the boy's uncle rather than his biological father.
Genzo in the TV seriesEdit
Genzo in the Manga / 12 part OAVEdit
We first see Genzo yelling at the group of Zoanoid soldiers that had been sent out to deal with the strange creature that had appeared at the lake, berating them and telling them that the "other Zoanoid" they had been facing was, in fact, the very Guyver they had been sent out to search for. Inspector Lisker, who was in his office at the time, was not particularly impressed with any of their performances. He said that he had known from the start that they would fail their mission, especially with Genzo himself in charge.
Changing the subject, Lisker instead spoke about the Guyver; fitting, since he had been dispatched to oversee the retrieval of the Units themselves.
When one of the Units had been recovered, Genzo offered to show it to Lisker personally; Lisker accepted, making a not-so-oblique threat as to what kind of punishment he would devise for Genzo if the Unit were damaged in some way. The viewing went well, up until the case containing the Unit was opened. Then, Genzo watched in shocked horror as the Unit enveloped Lisker in its unformed, tentacled mass.
Later, when Genzo spoke to Lisker once more, he found himself arguing fervently against the Inspector's stated intention: to take the battle to the Guyver before the boy could decide to hunt them down. Genzo attempted to persuade Lisker to stay, stating that Lisker's possession of the Guyver made him far too valuable to the company to risk himself in battle until they had been able to obtain more data on the Guyver. Lisker, in no mood to be delayed, dismissed Genzo's words and quickly departed to fight.
Genzo would still be held responsible for what happened next.
Richard Guyot soon arrived, not particularly pleased to see what a complete mess had been made of what had been originally a simple retrieval mission. Guyot told him that, while the Japan branch had made many useful advances in the past, they were nothing more than a footnote at this point in time. Leaving Genzo, with a stark promise to deal with him later, Guyot ordered his subordinate - the Hyper Zoanoid Zerebubuth - to deal with the Guyver, and also to bring him the two high school students who had encountered it.
However, Guyot was not about to allow Genzo to escape punishment for his failures.
Ordering that the former head of Chronos Japan be transformed into the prototype-Zoanoid Enzyme, Guyot didn't even allow enough time for the genetic alterations to fully stabilize, leaving Genzo with only a week to live. However, given how little Guyot cared for the man, given both his personality and repeated failures, it's clear Guyot didn't care about that.
Confronting Sho and Tetsuro in the same location that the two of them had found the Unit, Genzo transformed and attacked. True to his name as the first of Chronos' future line of Guyver-killers, Genzo as Enzyme was able to dispatch Guyver I and remove the Control Medal from his forehead. However, due to the armor's sheer resilience and plethora of weapons, Sho was also able to inflict near-fatal damage on Genzo-Enzyme as well.
Or, at least enough damage that Guyot decided to cut his losses and self-destruct Enzyme, pouring the Guyver-killer's corrosive blood over Guyver I's dissolving form.