Citrus unshiu is a citrus species commonly known as tangerine or mandarine. Its fruit is sweet and about the size of its sister mandarin orange, Citrus reticulata. One of the distinguishing features of the fruits of C. unshiu is the thin, leathery skin dotted with large and prominent oil glands.

Dried skin or the peel of C. unshiu has been widely used for medicinal purposes in Traditional Oriental Medicine to improve bronchial and asthmatic conditions or blood circulation. Tea, of its peel, can relieve cold symptoms and digestive disorders and enhance stamina. From November to February, the peels are dried for multiple purposes on wide fields on Jeju Island, which creates a unique scene with orange-colored fields.