premise: In Masamune's service, Akimitsu was acknowledged as chief among the heads of the Date clan's cadet branches, or "ichimon-hittō" (一門衆筆頭).
hypothesis: In Masamune 's service, Akimitsu was acknowledged as chief among the heads of the Date clan 's cadet branches, ichimon - hittō " 一門衆筆頭.