Hyō

is a member of Konoha's ANBU and a former member of the, now disbanded, ANBU "Root". As most Root ANBU, he's still loyal to Root's founder Danzō and is apparently trustworthy enough to be given the task of delivering top-secret information for him.

Search for Sasuke
Hyō visited his junior Sai just before the latter went on a top-secret mission for Root. Seeing that Sai still held on to a picture book from his past, Hyō reminded his junior about the will and purpose of Root.

Invasion of Pain
It is presumed that like all other members of the Foundation, Hyō was ordered by Danzo not to fight against Pain's attack on Konoha. This was so Danzo could take advantage of the situation and overthrow Tsunade and become the Sixth Hokage.