Yugito Nii

is a kunoichi from Kumogakure. When she was two years old, she became the jinchūriki of the Two-Tailed Monster Cat.

Hidan and Kakuzu arc
She is first seen running through the sewers from some unknown persons, later revealed to be Hidan and Kakuzu. When she enters a large room, where all the sewers seems to meet, she finally stops. After some bickering between the two Akatsuki members, she reveals that she intentionally led them there and activates an exploding tag on the tunnel behind them, sealing them off. Knowing that they are from Akatsuki, she transforms into a miniature version of the Two-Tails. However, after a 30-minute unseen battle, she is taken down by Hidan and brought to the Akatsuki lair. The Two-Tails is extracted from her body, resulting in her death.

It is later indicated that Kumogakure is furious over the loss of Yugito.

Abilities
The only part of her abilities ever seen in the series was the ability to turn into a version of the Two-Tails, giving her an upgrade in her abilities, such as strength and an ability to breathe fire. The way she transforms is very similar to Naruto, being slowly covered in a dense blue fire chakra that takes the form of her Tailed Beast. It would seem that although she lets go of her control over the Two-Tails, she still has some control over the transformation and how much of its chakra that she can use. Since her power is so great, she is forbidden to release her full form by the Raikage's orders.

Trivia

 * "Nii" means "second place" in Japanese.
 * When she makes an appearance on the cover of 420, her hair ties were gold. In the anime, they are white.