iPhone XS dual SIM card use in Japan
Does the dual SIM card on the iPhone XS work in Japan with SoftBank?
iPhone XS, iOS 12
Does the dual SIM card on the iPhone XS work in Japan with SoftBank?
iPhone XS, iOS 12
The eSIM does not support any providers in Japan according to this list.
https://support.apple.com/en-us/HT209096
You would have to use the regular nano-SIM card physically for your carrier in Japan, and use a supported provider on the eSIM.
iPhone XS dual SIM card use in Japan