You MUST:

 be a citizen or a national of Australia, New Zealand, Canada, the Republic of Korea, Germany, France or the United Kingdom currently residing in your country of citizenship.
 stay in Japan mostly to holiday, for a specific length of time.
 be between the ages of 18 and 30 at the time of application.
 possess a valid passport and a return ticket or sufficient funds to purchase a return ticket.
 have reasonable funds for living expenses, including medical expenses, during the period of your initial stay in Japan. For a single person, the minimum requirement is US$2000 or equivalent amount of the national currency. And for a married couple the minimum requirement is US$3000 or equivalent amount of the national currency.
 be in good health and must not have a criminal record.