The Osing or Using (Osing: Lare Osing; Lare Using) are sub-ethnic group of Javanese native to easternmost part of the Java island (especially in Banyuwangi), Indonesia. They are the descendants of the people of the ancient Kingdom of Blambangan. The population of Osing people are approximately 400,000 which concentrated in the Banyuwangi Regency of East Java Province