She was fully humiliated by Yukimura at a young age and still carries a grudge against her, and was sent by Sen's brother Yoshihiko to spy on Sen and Yukimura's actions. Her weapon is a decorated, over-sized sledgehammer capable of knocking heavy gates and create fissures when slammed down to the ground.
Later in the series she feels responsible for being a liability on the dojo and decides to sneak away silently in the night, but ends up getting ambushed by Araki Mataemon. Defeated soon after, Mataemon throws Kanetsugu into a street canal the moment Muneakira reaches there looking for her. Rescuing an unconscious and near death Kantsugu, Muneakira proceeds to resuscitate her by performing CPR but at the same time cries at the dreaded thought of losing her should he fail. This emotional state of Muneakira connects with Kanetsugu's dying state at a spiritual level giving life to a new bond between the two changing the next CPR attempt into a contract kiss turning Kanetsugu into Muneakira's Fifth Master Samurai.
Her weapon of choice is a decorated sledgehammer capable of knocking heavy gates and creating fissures when slammed down to ground.