Okay kiddo, you know how we have different types of things we like to watch or listen to, right? Like cartoons or songs on the radio? Well, in Japan they have lots of things like that too, and they call it 'pop culture'.
Sometimes, people in America really like the things that come from Japan, like anime (which are cartoons from Japan), or J-Pop (which is music from Japan that's popular). So they want to watch and listen to these things too!
That means that some of these things get brought over to America, so people here can enjoy them too. Sometimes, they even make changes to the things from Japan to fit better with what people here like.
And because people in America think these things are so cool, they might even dress up like the characters from their favorite anime or go to events where they can meet other people who like the same things!
Overall, Japanese pop culture has become really popular in the United States and it's fun for people here to enjoy all the cool and interesting things that come from Japan.