Sound Four

The Sound Four (音隠れの忍四人衆, literally Hidden Sound Shinobi Four People) were Orochimaru's elite bodyguards (Sakon and Ukon are counted as one entity due to their kekkei genkai). Each was given a cursed seal by Orochimaru. They were all defeated and killed by Naruto's friends and Gaara's siblings in the Sasuke Retrieval arc. Kimimaro Kaguya was a part of the group for a short time, since he was stronger than all four combined, and was intended to be Orochimaru's next host, but an unexpected illness prevented him from participating normally. All five repeatedly refer to their opponents as "trash".

The Sound Four were all talented in barrier jutsu. When first seen the four use to create a box-like barrier around the area of Orochimaru's battle, causing anything that touches to burst into flames. To prevent themselves from being attacked and thus bringing down the barrier, the Sound Four created the same barrier around themselves. When the group later fetches Sasuke Uchiha, the four use on him to put him into a coma, preventing his death while his cursed seal advances. When Sasuke is put into a barrel while his seal advances, Sakon puts a seal on the barrel with to protect Sasuke from harm. As the group later rests, they set up a by placing four exploding tags in an array around where they are. When the tags are set, they create an invisible barrier around the area and will detonate should anyone pass the barrier, killing the intruder. Each member of the Sound Four also has a cardinal direction associated with them; this is probably a reference to their positions when performing jutsu as a group.

Of the sound four only Kidomaru wore a headband, perhaps because they were missing-nin or because the others were never officially trained, only taught by Orochimaru (Note that this is only speculation).