Upvote:4
From the Ministry of Foreign Affairs of Japan:
Q5: Can I apply for a visa at the nearest Japanese Embassy / Consulate General while traveling in a foreign country?
A5: You can apply for the visa at the Japanese Embassy / Consulate General in your own country (region) or country (region) of residence (if there is more than one, apply to the Japanese Embassy / Consulate General nearest from where you live). In other words, you cannot apply for a visa at your travel destination; however, if there are unavoidable circumstances, consult with the Japanese Embassy / Consulate General where you would like to apply for the visa before making the application.