JETRO/Japan External Trade Organization
A comprehensive consultation window for all things related to exports including policies of the country the item is being exported to.
https://www.jetro.go.jp/services/advice/agri_foods
Ministry of Agriculture,Forestry and Fisherise
Here you will find consultation about export of agriculture/foods by genre and item.
http://www.maff.go.jp/j/shokusan/export/tantou.html
Japan Tea Export Council
A group that supports various operations that aims to promote the diffusion/export of Japanese tea towards foreign countries.