Matsunaga Stone Co. Ltd was established in 1948 and King is one of the most well-known brands for Japanese sharpening stones. The company head office is in Osaka with branch offices in Fukuoka, Niigata and Sapporo. The company specialises in abrasives, grinding wheels and sharpening stones of various kinds. It also manufactures the Sun Tiger range of stones. The current president is Hiroyuki Matsunaga.