Jinchūriki

The are humans that have Tailed Beasts sealed within them. They exhibit extraordinary powers, and in some cases are more powerful than their tailed beasts, because they have the intelligence to use the beasts' powers effectively.

The jinchūriki are typically lonely people, viewed by those around them as the tailed beasts that had been sealed within them, leading to prejudice and being hated and feared. According to Akatsuki, the first two jinchūriki they captured loathed humanity, and their villages were in fact glad to be rid of them. However, some jinchūriki refuse to waver, even though they have been shunned, and they eventually earned respect. Such examples are Naruto, Killer B, and the most prominent being Gaara.

Sealing
Each village has used a different seal when creating their jinchūriki. For example, Konoha used the Eight Trigrams Sealing Style, and w:c:naruto:Kumogakure used the Iron Armour Seal. Akatsuki, an organisation whose role in the series is to capture the jinchūriki, uses the Sealing Technique: Phantom Dragons Nine Consuming Seals technique to extract and seal the tailed beasts within the Demonic Statue of the Outer Path for future use.

If the tailed beast is removed from its jinchūriki's body, the jinchūriki will die. Similarly, if the jinchūriki dies with the tailed beast still sealed within them, the beast will die too. Because of this, the tailed beasts tend to be very protective of their jinchūriki, and will take any action whenever their lives are in danger. However, this was not always the case. Before the Nine-Tails was sealed into Naruto, it was said that it could actually survive its jinchūriki's death, with the only consequence being that it would take time for it to be revived. Also, rare exceptions of a jinchūriki surviving an extraction may occur, if the said host has high enough stamina.

The seal that keep the tailed beast within its female jinchūriki is at its weakest when she is in childbirth, due to the nurturing of the child in the womb taking precedence over the reinforcement of the seal which weakens the seal in direct proportion. As such, a ninja is required to keep the seal intact during childbirth, and restore the seal back to full power afterwards. A full-term pregnancy for a female jinchūriki is about ten months.

Abilities
The jinchūriki have shown to have access to great amounts of chakra and access to unique fighting styles and abilities, depending on their tailed beast: Gaara manipulates sand, Yugito breathes fire, Rōshi creates and manipulates lava, Fū is capable of flight, Killer B spits ink, and Naruto has quick regeneration. By training, they can gain additional access to their tailed beast and its chakra, such as Yugito being able to control her transformations, Killer B being able to synchronise with the Eight-Tails, and transform himself into it, and Naruto accessing the Nine-Tails' Yang chakra only when he needs it which gives him a chakra shroud that resembles the Sage of the Six Paths, and is able to sense negative emotions.