Yes, on eligible versions.
Nothing limits eSIM on the standard Phone (3a) to units sold in Japan. Rakuten lists nano-SIM and eSIM on its A059. Check the original sales market as well as the model number.
See manufacturer evidence View family overviewModel data (JSON)Hardware model numbers
Match the model number in Settings to see which version you have.
Check your phone
Match the model number
Open Settings → About phone (or About device). Match the number and original sales region against the manufacturer’s specifications.
Find the eSIM settings
Look for EID in your device information. An IMEI alone does not prove eSIM support. Check Settings → SIMs or Mobile network and the option to add or download an eSIM; menu names vary.
Confirm carrier unlocking
Ask the carrier that originally sold the device to confirm it is network-unlocked and can use another provider’s eSIM. Android does not have one lock-status menu shared by every brand. Your provider still needs to support your device.
Official evidence
Each regional source covers the models sold in that market.