You can sign up for Alipay and use it in China, but you cannot use it in other countries because that privilege is only limited to those with Chinese ID cards. Same goes with Wechat pay if you are wondering.
Are you sure about this? Alipay is accepted in many shops in Japan now. Are you saying only Chinese people can pay with Alipay in Japan? Japanese people cannot use Alipay in Japan?
Only PRC citizens can use Alipay or Wechat Pay overseas. That's why they had to come up with the HK version. Japanese people cannot use the Mainland version of Alipay in Japan.
Wow, the number of stores in Japan accepting Alipay has increased from 50,000 to 300,000 in the last 12 months. I tried to use it in 7-11 but my QR code wouldn't work. I assumed because I was using AlipayHK and not Alipay. Now your telling me it's only for Chinese tourists? It's quite amazing the lengths the Japanese will go in order to please Chinese tourists, Alipay logo's are quite common around Japan but Japanese cant use it, every other tourist in the world can't use it either except Chinese? To me this sounds crazy.