The Ichimonji (the character for number one) group inscribed their names with '一' (One) and Norimune's swords had a chrysanthemum inscribed, so they were called Kikuichimonji.
一文字派は銘を「一」とだけ彫り、この刀はそれに加えて菊の紋を彫ったので菊一文字と称するようになった。