Ninja Hattori-kun is a very obscure series in North America. The series has never been brought to the United States of America, though there are some people who know about the series.
In late 2017, a Nickelodeon India Teacher's Day commercial became a viral video in North America. The video was about dabbing and it briefly featured Hattori and Kenichi. A series of live-action commercials also became viral due to the funny-looking Hattori costumes. These viral videos led to the series gaining a few American fans.
The meme has declined in popularity since 2017, though there a few people who are still making memes and edits. These people include Whip and Garfielf64, among others.
The two main English-speaking fan groups are the Ninja Hattori Wiki and the Discord server. The wiki is a knowledge-base where people can write about the various characters and episodes of the series. The Discord server allows people to talk to each other about the series and watch new episodes together. Some fans are part of the Shin-Chan Discord server, where several shows are discussed, including Shin-Chan and Ninja Hattori-kun.