"Date Hikan" (the secret records of Date) written by a retainer of Sendai Domain, Michitoki HANDA has a description stating there was a group of ninja (Japanese covert agent in feudal times) called Kurohabagigumi (Black shin guards Corps).
また、黒脛巾組という忍者集団がいたと仙台藩士の半田道時の伊達秘鑑には掲載されている。