(유자) – Citron is a citrus fruit with a very fragrant zest that seems to combine the flavors of lemon, orange, and grapefruit. The fruit originates from China but is most popular in Korea, where it is known as yuja (유자), and Japan, where it is known as yuzu (ゆず). In both countries it is popular as a tea and is used in other foods as well, mostly in desserts. You probably won’t find this ice cream available for sale anywhere else, though it has been seen in some shops in Asia.