Ototon

Techniques
Over the years the plenty years of constant experimentation with the human body and the transferring of genes to such for a desired effect has led Otogakure to acquire its own unique abilities custom to the land. Such abilities are strictly forbidden to be taught without approval of the creators in which it must take time of teaching and applying said abilities for one to be able to condone such. Some known abilities Otogakure has shown the shinobi world would be the use of sound waves to deteriorate the bone structure within humans to their own advantage; Sound Release. With such abilities Otogakure has a fine means of keeping them within its homeland. Those taught have only been known to be utmost loyal shinobi for if they were to get away with such information the nin would be immediately targeted upon all missing nin charts in which most wouldn't have enough information to teach others though Oto has a certain policy of forbidding others to witness such grand techniques without receiving it from the other end.

Ototon (In-depth) 6/1/14
All known users are being contacted and made to sign a contract restricting them to teach Ototon. This contract is immune to even those techniques granted via the human path and even Eye Mind Reading jutsu. those who refuse to abide by the above are to be killed on sight. From hereon anyone claiming to use Ototon without having learned it from the Otokage are to be voided. Even through use of mechanical means is not to be tolerated and will be seen as Ototon, thus voided.

Known Sound Release users: Known Poison Release users: Those who can teach Ototon;
 * Trev (Dead)
 * Hazama
 * Takeo Hyūga (Inactive)
 * Kimimaro Kaguya (Inactive)
 * Zekkō Zō
 * Yasei, Kurōn
 * Mikoto Hyūga
 * Genesis Uzumaki
 * ℭ⑂αηїḓ℮ Soul
 * Shadow (Alive; Can teach)
 * Menma Beleren
 * Vex
 * Zero Kurama (Trev)
 * Soya
 * Taumaster
 * Trev
 * Soya
 * Shadow
 * Shadow
 * Trev
 * Kamui