Earlier quoted context omitted.
On the contrary, if you are running a business where 99% of your customers are outside of the EU, its totally rational versus opening yourself up to massive liability.
You need to purge that 1% customer data though. If you're accepting EU citizens data through any channel - another business, them using a VPN, via smoke signals, you need to comply.
If the customer joins your Japanese site while in Japan, its governed under Japanese law, not EU law. Your citizenship is irrelevant.