Kabosu citrus is similar to lime, and it has a similar aroma and sour taste. While it’s well known throughout Oita, which is the biggest producer in Japan, it is most associated with the cities of Usuki and Taketa. It is a popular flavour in souveneir goods, and you’ll find it added as flavouring to a variety of other foods from grilled fish, sashimi, ponzu sauce, nabe, miso soup, and shōchū.