Otogakure

is Orochimaru's personal village, founded for the express purpose of collecting ninja for his experiments and quest to learn jutsu. In actuallity, Oto is not really a village but a group of hideouts and bases scattered through out the Land of Sound and other countries. Three Sound ninja (Dosu Kinuta, Zaku Abumi, and Kin Tsuchi), under Orochimaru's orders, entered the Chunin Exam with the goal of killing Sasuke Uchiha. However, Orochimaru was actually using them as test subjects for Sasuke's power after Orochimaru gave him the cursed seal. Later, Dosu is killed of by Gaara and Orochimaru sacrifices the other two. Oto's ninja use a diverse amount of different jutsu. The Oto symbol is an eighth note.

Orochimaru
Orochimaru is the leader of the village. Though he is not a Kage, he has been nicknamed the Otokage ("Sound Shadow") by fans due to his Kage-level power and knowledge. Orochimaru is also one of the Sannin. Though he is essentially the military dictator of Oto, he does not live in it. For most of the series, he is seen using a secret underground base as his headquarters. After Sasuke joins him, Kabuto mentions that they move into a new base every week.

Kabuto
Kabuto is currently the leader of Oto since Orochimaru's death, he integrated Orochimaru's remains into himself, giving him all of Orochimaru's powers. Allowing him to finish Orochimaru's goals as a leader not a follower.

Team Dosu
The Sound Genin are entered into the Chunin Exams by Orochimaru under the orders to kill Sasuke Uchiha. In reality, however, they are simply meant to test Sasuke's abilities, with Orochimaru having little concern for what happens to them afterwards. Dosu Kinuta was killed by Gaara, Zaku and Kin were killed by Orochimaru.

The bodies of Zaku and Kin were used by Orochimaru in his Summoning: Impure World Resurrection technique to re-animate Hashirama (1st Hokage) and Tobirama Senju (2nd Hokage). Many fans speculate that Dosu's body was to be used for Minato Namikaze (4th Hokage), but this is unproven since Minato's soul was already sealed as a result of the Dead Demon Consuming Seal and also because Dosu was killed by Gaara a month before the battle even took place.

Kabuto's Genin Team
Kabuto Yakushi's team is entered into the Chunin Exams as Konoha ninja to spy on their fellow participants for Orochimaru. The Jonin in charge of their team is Orochimaru in disguise. He reveals himself to Kakashi Hatake after Kakashi seals Sasuke Uchiha's Cursed Seal of Heaven. Kabuto seems to operate without Yoroi and Misumi during the exams, as he is rarely seen with them.

Misumi Tsurugi is presumed deceased.

Yoroi Akado is presumed deceased.

Sound Four
The Sound Four was Orochimaru's elite ninja squad consisting of four possible Chunin level ninja each branded with Orochimaru's Juinjutsu, the Sound Four's Cursed Seals. When not on assignments, they act as his personal guard. The Sound Four were killed in the Sasuke Retrival arc.

Other citizens

 * Amachi
 * Fūma clan
 * Kimimaro