What are the departure and arrival procedures at the airport?

There are quarantine measures, immigration and customs clearance.
Quarantine procedures include submission of documents (COVID-19 negative test result certificate before departure, vaccination certificate, questionnaire, written pledge, etc.), installing and setting up apps, and on-arrival tests for new coronavirus at the airport. Your required procedures will depend on the classification of the country or region of your stay before arrival, your vaccination status, or other factors. Preparation may be required prior to entry into Japan, so please check the Ministry of Health, Labor and Welfare website (Japanese/English) for the most up-to-date information.