Shiranui (不知火) is a seedless, sweet variety of satsuma orange, originally developed in Japan, where it is marketed as Dekopon (デコポン). It is also cultivated in the United States as Sumo Citrus, in Korea as hallabong, and Brazil as Kinsei.
Shiranui fruit is large, sweet, and has a distinctive protruding bump at the top of the fruit.