What if I have paid 8% tax as above, can I get refund?
How to get refund from Japan?
You need to register in Japan before the date that invoice is issued.
If you want to get refund, you definitely need to register in Japan.
Even nothing to refund in shortly, you still can voluntarily register in Japan. Just in case in the future you need to refund.
How long we can get refunded after i submitted claim?
Around one month.