Ambrose walked down the street with a small rock in his hand. He used his left hand to juggle with it and fiddle with his fingers. It was another training session to improve his non-dominant hand, and he did this whenever he could.
As he kept doing that, he soon came across a street with many open dojos. A few of them were NPC dojos, while most of them were player dojos.
There were long lines in front of the player dojos. The players wanted to join the dojos to learn skills so that the "Master" of the dojo could teach their techniques to them. The master title belonged to the owner of the dojo.
Even Ambrose could teach his Kill skill to his students, if he had any, but it was far from easy to learn. Most dojos also take payments from their students, which they use to fund their training and adventures.
It was a good way of earning money, but most of it didn't end up in the master's pocket. Having a dojo with many students was expensive.