Taro is a pet dog from Niigata.
Masamune Kurohabaki apparently asked him for advice on finding Kenshin Nokizaru. Taro was afraid of Masamune and barked and growled at it so loudly that its owner shouted at her from the window and told her to be silent.
Later, Unsai sends his shinobi to the city to ring alarm bells to gather his army. Taro answers the call with the other pets.