Yukishiro Tomoe was the daughter of a well-to-do samurai family that remained on the side of the Bakufu during the bakumatsu and was engaged to her childhood friend Kiyosato Akira. However, when Akira was slain by the Hitokiri Himura Battōsai, Tomoe leaves home and joins the Yaminobu in order to avenge her fiancé. However, after tracking Battōsai down, she slowly falls in love with him and becomes his wife instead. As the Yaminobu close their net around Himura, Tomoe intervenes and, saving her new husband's life, becomes a casualty herself - cut down by Himura's own sword. As such, Tomoe becomes Himura's primary motivation in his oath never to take another life as well as the motivation for her younger brother Enishi's revenge.