In case you are need for some inspiration in the wake of Schrems II..
https://ico.org.uk/media/for-organisations/documents/1529/assessing_adequacy_international_data_transfers.pdf
European Commission adopts adequacy decision on Japan, creating the world’s largest area of safe data flows
http://europa.eu/rapid/press-release_IP-19-421_en.htm
Japan adequacy decision and related documents
https://ec.europa.eu/info/law/law-topic/data-protection/data-transfers-outside-eu/adequacy-protection-personal-data-non-eu-countries_en