Okay kiddo, so ittatsu-ryū is something called a martial art. That means it's a way for people to learn how to fight and defend themselves. Have you ever seen somebody do karate or judo on TV or in a movie? It's kind of like that, but ittatsu-ryū is its own unique style of martial art.
In this type of martial art, people learn how to use their bodies and different weapons to protect themselves and fight off attackers. They might use things like swords or sticks to help them do this.
It's also important to learn things like balance, focus, and quick reflexes. These are skills that help people be really good at ittatsu-ryū - kind of like how playing lots of soccer can make you really good at kicking a ball.
People who practice ittatsu-ryū train really hard to get really good at it. They might have to do things like punch bags or practice blocking attacks over and over. And of course, they always have to be careful not to hurt themselves or each other!
In short, ittatsu-ryū is a special way to learn how to fight and protect oneself using weapons and special skills. It takes lots of practice and hard work to get really good at it!