The Kokubun clan (in Mutsu Province) is samurai, who had possessed the southern part of Miyagi County, Mutsu Province from the period of the Northern and Southern Courts to the Sengoku period (period of warring states).
国分氏(陸奥国)は、南北朝時代(日本)から戦国時代(日本)まで陸奥国宮城郡南部を領した武士である。