Election type

Ministry of Internal Affairs and Communications (総務省), Voting System: 4. Overseas Electoral System (投票制度 : 在外選挙制度), accessed 14 April 2025

4. 在外選挙制度 仕事や留学などで海外に住んでいる人が、外国にいながら国政選挙や最高裁判所裁判官国民審査に投票できる制度を「在外投票制度」といいます。在外投票ができるのは、日本国籍を持つ18歳以上の有権者で、在外選挙人名簿に登録され在外選挙人証を持っている人です。 在外選挙人名簿への登録の申請には、出国前に国外への転出届を提出する場合に市区町村の窓口で申請する方法（出国時申請）と、出国後に居住している地域を管轄する日本大使館・総領事館（領事事務所を含みます。）に申請する方法（在外公館申請）があります。 投票の方法には、在外公館で行う「在外公館投票」、郵便等によって行う「郵便等投票」、選挙の際に一時帰国した人や帰国後間もないため国内の選挙人名簿にまだ登録されていない人が行う「日本国内における投票」があります。 在外投票の対象は、衆議院議員選挙、参議院議員選挙及び最高裁判所裁判官国民審査です。

unofficial translation:

4. Overseas Electoral System 

The "overseas voting system" is a system that allows people living abroad for work or study abroad to vote in national elections and the national examination of Supreme Court judges while they are abroad. Voters aged 18 and over with Japanese nationality are eligible to vote overseas, are registered on the overseas electoral roll, and hold an overseas voter card. To apply for registration on the overseas electoral roll, you can apply at the window of your municipality when submitting a notification of moving out of Japan before leaving Japan (application at the time of departure), or at the Japan embassy or consulate general (including consular offices) that has jurisdiction over the area where you reside after leaving Japan. There is a way to apply (Diplomatic Mission Abroad). There are three ways to vote: "voting at diplomatic missions abroad," "voting by mail," etc., by mail, etc., and "voting in Japan," which is conducted by people who have temporarily returned to Japan at the time of the election or who have not yet been registered on the electoral roll in Japan because they have recently returned to Japan.

Overseas voting is subject to the election of members of the House of Representatives, the House of Councilors, and the national examination of Supreme Court judges.