World of Naruto - Phenomena - Tailed Beasts - Jinchuriki

The Jinchuriki (人柱力, lit. "Power of Human Sacrifice"?), or simply hosts, are humans who have had a Tailed Beast sealed into their bodies. The first one to perform this was the Sage of the Six Paths when he needed to subdue the Ten-Tails. Later Jinchūriki are created by ninja villages so they would have an advantage over their rivals. In most instances, they are actually stronger than the Tailed Beasts they contain, as they have the knowledge to effectively control the Tailed Beast's strength. Each of the hosts appear to have a physical characteristic that resembles their beast; Naruto has fox-like whisker-marks on his face, while Gaara has tanuki-like rings around his eyes. Other than them and Killer Bee, the most recent Jinchūriki of the other Tailed Beasts include Yugito Nii (二位ユギト?), the Fourth Mizukage Yagura (やぐら?), Rōshi (老紫?), Han (ハン?), the rogue ninja Utakata (ウタカタ?), and Fū (フウ?). The six were each killed off by the Akatsuki and their corpses altered by Tobi to become his personal Six Paths of Pain and with their former Tailed Beasts sealed back inside of them.

According to members of the Akatsuki, hosts of Tailed Beasts are typically lonely people who loathe humanity. When Akatsuki captured their first two Jinchūriki, no one from their villages cared, and in fact were thankful to be rid of them. Normally, if a beast is removed from its host's body, the host would immediately die, unless they possess a long lifespan like that of the Uzumaki clan. Similarly if the host dies with the beast still sealed within them, the beast would die too. Because of this, Tailed Beasts tend to be protective of their hosts to the point of taking over their hosts' bodies if needed to. Hosts can communicate with their beast in an effort to use the beast's powers at will. Killer Bee (Gyūki's host) seems to have had the most success in doing so, having a mutual and strong relationship with his beast and being able to fully unleash the beast within him while still maintaining his sense of self. Naruto was the opposite, originally in conflict with Kurama and losing control over himself when he reached four tails or more. But eventually, Naruto was able to defeat Kurama and forcefully consume its chakra to enter the "Tailed Beast Chakra Mode"; later forming an equal partnership with Kurama when Naruto shows kindness to its fellow Tailed Beasts in his attempt to save them from Obito before he sacrificed them to revive the Ten-Tails.