American animation and Japanese animation are so different from each other that it often feels like they are both made on two different planets.

When I was a kid growing up in the nineties, the cartoons I watched that first shaped me into the animation geek that I am today were Nicktoons, Looney Tunes and Disney films which were all obviously American. Disney had always promoted moral values in their films and Warner Bros. cartoons were packed with American pop-culture references, and since I grew up on these films, alongside very American things like the Muppets, The Wizard of Oz and Charlie Brown, I was a very American kid.

But a lot of things happened in the late nineties and early 2000s that significantly changed the way I looked at entertainment. I discovered video games. I discovered comic books. I watched Star Wars for the first time. Most startling of all was when I first watched anime.

These four things have something in common. They were not the same as watching Darkwing Duck or the antics of Tom and Jerry. They were allowing me to enter new worlds. Worlds I could control (video games), worlds with an entire mythology (Star Wars) and worlds that were so huge it was impossible to explore every corner (Marvel comics), but the worlds all felt real and immersive and they weren’t just passive entertainment. I finally understood what it felt like to be a true geek. There’s no better example of this than the Pokémon series.

The Pokémon TV show was the first anime to infiltrate the American mainstream. The first season aired daily in syndication on UPN before moving to Kids’ WB. I had seen episodes of Dragon Ball Z and Sailor Moon before but Pokémon was the first time I became fully engaged in an anime cartoon and it may very well signify my first obsession with a cartoon in general. The accompanying Game Boy games certainly helped with that immersion.

For a long time if you had asked me what my favorite TV show was in the nineties, I would have said Rugrats, but that completely changed after watching Pokémon, which was a show unlike anything I had ever seen. It introduced many anime tropes to American audiences for the first time: the big eyes, the crazy hair, the comically exaggerated facial expressions that changed to match the character’s emotions, and the neverending hero’s quest, which in anime often featured children in lead roles.

One of the reasons for the financial success of the Pokémon franchise is its cross-media ubiquity. In addition to the video games and the anime, Pokémon are featured on trading cards, watches, backpacks, cereal and are made into stuffed animals. The sheer amount of Pokémon in the series, of which there were initially 150, made Pokémon’s market value in the toy business unchallenged, even by Star Wars and Harry Potter. The franchise is still going strong today.

Thanks to the success of that show, other Japanese TV shows were translated and dubbed and they also gained a large amount of American fans, including Yu-Gi-Oh!, Naruto and One Piece. Many Americans discovered anime by watching Kids’ WB, Toonami and Adult Swim and they continue to be delivered to Americans online via Netflix, Hulu and Crunchyroll via American distributors Viz Media and Funimation.

American films like The Matrix and Kill Bill are directly influenced by anime, and American cartoons influenced by Japan include The Powerpuff Girls, Teen Titans, Hi Hi PuffyAmiyumi and Avatar: The Last Airbender. Before the American anime invasion, television animation had been going in the direction of a fuller quality, as evidenced by shows like Gummi Bears and Animaniacs. But anime’s minimalist art style and simplistic animation was much more appealing to kids, and ironically, American shows like The Simpsons, Beavis and Butt-Head and South Park may have played a part in helping Americans transition into their acceptance of that minimal style more smoothly. The resistance towards fuller and more realistic animation in favor of simpler and more stylized art has been around since the 1940s when people left Disney to work at UPA. This is why it’s always important to have all kinds of different animation to appeal to all tastes. It keeps the medium alive and healthy.

Of course the popularity of anime has brought with it more than just a new type of animation. Ever since the 2000s, the words “anime,” “manga” and “otaku” are in common use in America, and now you see a rise in Americans learning how to speak Japanese, entire sections of libraries dedicated to manga, and anime conventions held in the States every week. We are in the middle of a Japanese invasion.