- Age: 14 (deceased)
- Seiyu: Shunsuke Sakuya
- Voice Actor: Brian Beacock
- Sakon (左近) and the older brother Ukon (右近) are twin brothers who share positions in the Sound Four. To help distinguish between the two, Sakon wears beads around his neck and Ukon has a somewhat deeper voice. With their kekkei genkai, Sakon and Ukon are able to merge with the bodies of others. Ukon generally uses this ability to remain within Sakon's body where he can bring out some of his body parts to aid Sakon in blocking or attacking. Ukon can separate from Sakon's body so that the two can attack independently, though he is not used to moving on his own and thus tires easily. In addition to combining with each other, Sakon or Ukon can merge with an opponent's body, destroying their cells from the inside to slowly kill them. While within another's body, however, they are vulnerable to whatever injuries befall upon the host, in theory allowing the host to commit suicide to kill either of the brothers. This ability also gives the two regenerative capabilities, and given enough time they can recover from any wound.
Sakon and Ukon are enjoy bad-mouthing the opposition. Orochimaru notes Sakon to be the fastest and strongest member of the Sound Four, traits Sakon is very proud of. When in battle Sakon likes to prolong the fight by toying with the opponent and all the while use unnecessarily powerful techniques. This tendency of Sakon's causes him to slow down the rest of the group whenever he gets interested in an opponent. Ukon is able to counteract this flaw by being more impatient and hasty than his brother, forcing Sakon to quickly end his battles. During the Sasuke Retrieval arc, Sakon and Ukon fight and almost kill Kiba Inuzuka and Akamaru. Before they can finish the two off, however, Kankuro arrives and kills them both with his puppets, saving Kiba and Akamaru.
Sakon was the final member of the Sound Four to be created by Masashi Kishimoto. After struggling to decide who Sakon should fight, Kishimoto decided to have Sakon take part in a two-on-two battle. Thus he created Ukon and placed him within Sakon's body so that they could act as one person.