Knopekin
Ya heard!
And from another perspective, I know that there are lots of people from other countries too who are obsessed with Britain and "British accents" and assume that we're all posh and enjoy tea parties and are often too polite for our own good - some of those stereotypes are true, but there is a lot Britain than that lmao, it just feels a little bit shallow and like they are just basing our country off of stereotypes and judgments, which is a normal thing to do I think, it's so quick to judge something just based on what you see and how it's portrayed in the media and so on, but we have to realise that these are just very shallow judgments and they can be insulting to people sometimes.
People doing that are somewhere between 'annoying' and 'shallow', but are definitely not offensive or hurting anyone. The same way that a British person wouldn't be offended that someone foreign thought the UK was all about the royal family/Shakespeare/Doctor Who/whatever, I don't think that anybody Japanese would think a foreigner who loved anime and video games was insulting because they loved Japan based on their hobbies.