Hashi

Hashi (橋) is a branch of Soragakure`s Anbu.

Overview
Hashi was a division of the Anbu class of Soragakure and was controlled by Fudou Murano, the right-hand man of the Second Tsukikage. It was first supposed to be a reserve of shinobi in Anbu-level to be used during wars and supervised by the Tsukikage, but some time after its creation, it started having its own missions (that Fudou estabilished), with its ninjas being the only ones that could fulfill and know about them.

Fudou sees Hashi`s secrecy as its main point, and the only people who know the organization exists are the Tsukikages, the most skilled members of the Anbu, Fudou himself and its members. Due to that point of view of his, he established some rules to make sure nobody apart from those would ever suspect of Hashi`s existence: Hashi members are personally chosen by Fudou, who uses his judgement to discover the most skilled ninjas there are and proposes them to join the organization. Many members only accept and stay loyal because of fear. Hashi is said to possess many strict rules, the main one being that members must sacrifice anything, including their lives, for the mission to be accomplished.
 * Fudou implanted cursed seals on the heads of all members, so that if any of them try speaking about the organization, the cursed seal will activate, causing the destruction of their brain cells and eventual death.
 * Once a ninja enters the organization they are strictly forbidden to leave.
 * Any member of Hashi that is considered by Fudou to "know too much" is executed.
 * Any intruders in the chambers of Hashi must be executed immediately.
 * Anyone who is suspected to know anything about the organization should be eliminated.

Hashi, like Sora`s Anbu, usually operates with two-man cells, and it`s seen that sometimes one Hashi member pairs with an Anbu member, though Fudou does that only when there is a mission to assassinate said Anbu member.

Assassinate Kumogakure Ninjas
Fudou had Keiichi and Yukimura ambush a group of ninjas from Kumo and kill them, for unknown reasons. As the Fourth Tsukikage had started suspecting of Hashi`s real intentions and reduced the equipment sent to the organization, Keiichi and Yukimura found themselves defenseless; Yukimura then decided to use a suicidal attack and exploded the whole are with an explosive tag, not before making sure Keiichi was distant enough to not be affected as he thought he would be useful to Hashi later.
 * Assigned to: Keiichi Aburaya and Yukimura
 * Outcome: Success

Trivia

 * Hashi is known as "the bridge that helps the Tsukikage reach the sky", a reference on how "hashi" means bridge and "sora" means sky. Basically, the sentence means that Hashi is what keeps Soragakure operating. Keiichi expresses his view with the sentence "all bridges eventually collapse, and when that happens, the only thing that remains is the sky", using the same reference to say that Hashi is absolutely useless to Soragakure`s development.
 * Keiichi is the only known ninja (and probably the only one) to be able to leave Hashi without dying and have his cursed seal removed by Fudou. That`s because he was protected by the Second and Fourth Tsukikages.