Unlike most constitutional monarchies, the Emperor is not even the nominal chief executive. He cannot participate in the electoral process or run for election to any public office. In regard to the Emperor's role, the Constitution of Japan explicitly states that the Emperor only "shall perform . . . . acts in matters of state as are provided for in the Constitution and he shall not have powers related to government" (article 4) and that the "advice and approval of the Cabinet shall be required for all acts of the Emperor in matters of state" (article 3, which also states that these duties can be delegated by the Emperor). Article 65 explicitly vests executive power in the Cabinet, of which the Prime Minister is the leader.

The duties the Emperor performs are closely regulated by the constitution. For example, while formally the Emperor's duties include appointing the Prime Minister to office, article 6 of the constitution requires him to appoint the candidate "as designated by the Diet" (in practice, the candidate designated by the House of Representatives) without the right to decline appointment. This is in marked contrast to his status under the Meiji Constitution, which recognized the emperor as the embodiment of all sovereign power of the realm.

The other detailed regulation of the Emperor's duties "in matters of state" (not government) is laid down in Article 7 of the constitution, where it is stated that the "Emperor with the advice and approval of the Cabinet, shall perform the following acts in matters of state on behalf of the people:

1. Promulgation of amendments of the constitution, laws, cabinet orders and treaties.
2. Convocation of the Diet.
3. Dissolution of the House of Representatives.
4. Proclamation of general election of members of the Diet.
5. Attestation of the appointment and dismissal of Ministers of State and other officials as provided for by law, and of full powers and credentials of Ambassadors and Ministers.
6. Attestation of general and special amnesty, commutation of punishment, reprieve, and restoration of rights.
7. Awarding of honors.
8. Attestation of instruments of ratification and other diplomatic documents as provided for by law.
9. Receiving foreign ambassadors and ministers.
10. Performance of ceremonial functions."