Hi quick question, for Asian-gaijin that understand N5, it's possible to blend in? And not get gaijin tax?
Well, good questions.
Unlike some other guys, I'd like to give you more insight:
1) JLPT doesn't have oral exam, so what JLPT level you have is totally not related to how good you SPEAK Japanese. The way you think is off-track from beginning.
2) If you want to enter a so called 'foreigner friendly' shop, you don't need to "blend in", they will most likely accept you if you look alright. Otherwise -
3) Whether you could 'blend in' not only depends on your Japanese level, but also how you act/be like a local, trust me, the staff will know you are foreigner in 5 seconds they meet you, just from your eyes, gesture and even clothes.
4) Tax, is a different topic, i don't think foreigner could avoid that easily but still possible with the slightest chance. It depends on how you negotiate with them and whether they want to do it for you, their mood on the day and so on, and again as i said above it's not related to your JLPT level.
Having said this, i am quite wondering which shop/provider you want to see in specific by 'blend in'? There are lots of shops openly accept foreigners now, if tax(budget) is a concern just find another shop costs less.