The Assassin Dolls are a squad of brainwashed puppets used by the Hyou Clan for assassination purposes. They are also responsible for protecting the clan from intruders and works as bodyguards.
The assassin dolls are actually members of the Hyou clan who were brainwashed and trained to be excellent assassins. They are skills are on par with those of the Wolves of the Wind. During Ou Tsuyuri's raid on the Hyou clan as the Black Wolf, the Assassin Dolls and the Wolves had taken each other out, eradicating both groups completely.