Choshu  "long state " is the common name for the Japanese feudal domain of Nagato  located at the western tip of Honshu in modern-day Yamaguchi prefecture During the rise of Tokugawa Ieyasu in the 1590's and 1600's  Choshu was one of the key "tozama domains" opposed to his rule  and its samurai were among those opposing him at Sekigahara*