Hou and Ban were Bount's sent to capture Uryuu Ishida. As twins, they dress identically (light brown sweatshirt, dark gray shorts with the pant legs rolled up and a yellow undershirt) with the exception of their hats. Ho wears a red baseball cap with short hair and Ban wears a white hat with long hair, parted down the middle. Despite looking like children, these twins are incredibly wise. Before fighting, they analyzed the enemy's power and adapted their strategy to fit. Being that their dolls are sentient, they stayed behind battle lines at the beginning, revealing only their lower face. In order to control their dolls, they telepathically link, so they often finish each other sentences.
(Source: Bleach Wikia)