No matter the age, there would always be some sly ones in the society who would be willing to use uncanny means to get the upper hand against their enemy. That was how the first ninja was born.
The first ninja was but a slave was made to do the dirty work of his master. While it was an extremely dishonorable job, yet when did slaves have any honor? It was supposed to be a detestable job done behind the shadows.
Yet little by little ninja hood grew to their own school of martial arts that everyone detested and feared. Even those at the top of the food chain couldn't stop their growth. They were always hidden in the shadows with no way to find them.
But when this school of thought had begun, they didn't have expensive tools and eye catching weapons. Most of the ancestral shinobis were slaves anyway. That is why they used whatever they got their hands on. From farming tools to simple kitchen knives! Anything that was sharp became their solace.
