The Food Sanitation Law of Japan provides that importers of any foods, food additives, tools, containers and packages thereof as well as toys for babies or infants, which are to be used for sale or business operation, should submit to the Minister of Health, Labour and Welfare a declaration on such import each time importation is made.

  For importing the said goods, it is necessary to submit the "Declaration on importation of food, etc." to a quarantine station first, and then submit to the customs the confirmed "Declaration on importation of food, etc." which has been issued by a food sanitation inspector with a seal certifying completed declaration. The customs’ confirmation of the completed declaration is requisite for obtaining import permission.

  It is provided that the submission of the declaration to the Minister of Health, Labour and Welfare is not necessary for those goods to be imported for private use or for test/experiment purposes. You should make sure whether your import goods can be regarded as those for private use or text/experiment purposes, prior to importation, by contacting a quarantine station of the Ministry of Health, Labour and Welfare.

(Article 70 of the Customs Law, item 1, section 3, paragraph 70 of the General Notification of the Customs Law, and Articles 27 and 62 of the Food Sanitation Law)

(reference) Website of the Ministry of Health, Labour and Welfare
   http://www.mhlw.go.jp/topics/yunyu/tp0130-1.html