Kato was not born a general. During the gang war nobody had heard of him. He was a working-class tiger from the lower districts who kept pulling people out of conflict zones because somebody had to.
What he understood before anyone else was that force alone would not end it. He went looking for individuals rather than institutions: Griff, an officer at the time; Raiju, who had been Griff's superior; Amy Lightfoot, the only super already working openly as a hero. He talked to many people. A few of them said yes.
Then something happened that no strategy accounted for. People began giving their Alpha to Kato and the ones who stood with him, because they believed in what he was arguing for. The war did not end because a handful of heroes won it. It ended because a city decided to back them. That is what the Grand Alliance means, and it is why the parade exists.
The parade is also the problem. As the League grew and its problems got larger, the community that made it possible slipped down the agenda. To the people of DeGen Alley it began to look like being forgotten, and warlords like Attikus Trask and Rat Rider moved into the space the League stopped watching.
Kato founded the Juniors Academy on the assumption that he will not always be here. He also keeps working relationships with the same politicians the rest of the League does not trust, which is the one thing Amy has never forgiven him for.