Having experience in both UK music culture and Tokyo life this film isn't as far off the mark as some people seem to think it is.
The Tokyo locations, mostly Shinjuku and easily recognisable to locals are well chosen, the language and culture barrier details are multilayered and well observed, and not done in a way to be actually stereotypical or derogatory.
The music industry is heavily managed in Japan, and image can be meticulously sculpted, just like in the US/UK manufactured pop scene.
Faded and fallen acts can have surprise success in Japan, - 90s wash outs Kula shaker playing festivals just a few years back!!, and that success is often devoid of it's original scene context, ie Japan will like mohawked punk without knowing about thatcher govt and the social and political scene that created it, they just like the look and sound of it and enjoy it on that level.
So this film got all of that right and delivered it with good humor, although it did cherry pick its cultural points specifically to forward the story, so practically none of the amazing positive things about Tokyo were shown; it's vibrancy, respect, deep culture and history, generous and deeply funny and fun people, self aware, smart, creative, that stuff doesn't really get much of a look in here, but that's fine, it's not the story they're telling.
So too it gets the deluded low level musicians of the electronic music scene. So many clever details (why have I got a guitar in my hand??), only got 2 songs, Beatles etc,
And then the social commentary is great.
"I've never received a salary in my whole life".
"I didn't enjoy it, but I loved it"
"It tastes normal" etc
A lot of this rings true and is pretty funny.
I know the Japan portrayed is supposed to play on that trope "oh those crazy japs " etc but, it's not that crazy when you live amongst it.