A citrus fruit orginating in East Asia believed to be a hybrid of sour mandarin and Ichang lemon, a Chinese citrus. It looks like a small grapefruit and has a strong lemon frangrance. While it does not produce a lot of juice the zest is frequently used in various cuisines. In Japan it is common to cut the fruit in half and place in a hot bath tub. Its fragrance is also often used in package bath and body products.