For such a small island nation, Japan has a surprisingly wide variety of citrus fruit. I saw some of them when I traveled in Japan last winter. Sadly, we don't get most of them here in the US, and I wish we did! It's so interesting to see such variety. Some of these varieties are used in flavoring tea and alcohol, others are used in marmalades, and some are eaten raw. I just love the green-skinned, orange-fleshed aomikan tangerine - it's so pretty!
Most of these fruits did not originate in Japan; many were brought over from China or Tibet hundreds of years ago. Here's a small sampling of the citrus fruit available in Japan:
Aomikan - a green tangerine that has orange flesh. Very tart, it makes a good marmalade. Available at the end of the summer from August to September.
Yuzu - a small, tart yellow citrus that is used to add flavor to soju and is a key ingredient in ponzu sauce. The zest is also used in cooking. Yuzu is used in winter solstice bathing ceremonies. Available from November to March.
Amanatsu - yellowish-orange and the size of a grapefruit, this fruit is eaten raw and used in marmalades.
Dekopon - a seedless and very sweet orange fruit with bumpy skin. Available in January and eaten raw and made into candies.
Kabosu - a tart, juicy green-skinned fruit with pale orange flesh. So tart that it is used as a vinegar substitute. It is also squeezed onto sashimi.
Sudachi - a green-skinned fruit available in summer. Very high acid content. Served with noodle dishes or nabe. Also used to flavor sojo, ice cream, and candies.
(Images: Kyoto Foodie and Wikipedia)