Jinchūriki Brothers

The Jinchūriki Brothers (人柱力兄弟, Jinchūriki Kyōdai) is the team formed after the Treaty of Higurashi, following Datara, the Ten-Tails, Kurama, the Nine-Tails, and Gyūki, the Eight-Tails, being sealed within Raian, Mashū, and one other unknown shinobi.

Background
The treaty of Higurashi took place two years after Seireitou Hyūga's botched Peace Requiem plan. The Kage from each nation formally agreed to accept the Land of Mountains as having equal status as their nations; allowing the Land's village, Yamagakure, to become an official part of the villages that make up the newly dubbed Great Shinobi Countries, as well as allowing their leader to have the official title of Kage.

This, however, did not come without terms. Yamagakure was supposed to be a neutral nation, meaning that its past alliances with other nations were dissolved in favor of making it and the Land of Mountains a "safe zone" for shinobi of all nations. Fear arose from the Yamakage, then Ryun Uchiha, that the nations would use their to intimidate Yamagakure to doing their bidding, despite the "no-alliance" rule. As a solution to this, the Kage determined that the remaining tailed beasts - Gyūki, the Eight-Tails, and Kurama, the Nine-Tails - would be handed over to Yamagakure to be sealed within new jinchūriki there.