Mito Uzumaki

was a kunoichi from Konohagakure's Senju clan who originated from Uzushiogakure's Uzumaki clan. She was also the first jinchūriki of the Nine-Tailed Demon Fox.

Background
The Uzumaki and Senju clans, being distant relatives, always had close ties. Mito ended up marrying Hashirama Senju, who would help found Konohagakure and become the village's First Hokage.

During her husband's battle against Madara Uchiha at the Valley of the End, Hashirama at some point gained control of the Nine-Tails. To gain power for Hashirama, Mito used a fūinjutsu to seal the Nine-Tails within herself, becoming the Nine-Tails' first jinchūriki. Despite the seal's strength, it almost broke at some later point when she was going through childbirth. Eventually, her husband died in war, and Mito was left a widow.

Towards the final years of her life, it was decided that a new host for the Nine-Tails would have to be found. Kushina Uzumaki, one of Mito's clansmen, was then selected for the role due to her special chakra, and was terrified by the idea. Mito comforted her however, and before the transfer was performed, told Kushina that love was the only way to counter the Nine-Tails' hatred.

Appearance
Mito had long hair and large, pupiless eyes. She wore an elaborate, high-collared kimono with the Uzushiogakure symbol on the back of the obi tied around her waist. Her hair was arranged in buns with hair pins in them and three clips in the front. She also wore a dark shade of lipstick and had a diamond mark on her forehead, similar to that of her granddaughter Tsunade. She also wore what appeared to be seal tags in her hair decals. In her old age, her hair had grown much longer some of which she allowed to hang into her back but maintained the two buns in her hair and wore a simple loose fitting kimono held closed by a simple dark-coloured obi.

Abilities
Not much is known about her fighting skills, but Kushina hailed her as a powerful kunoichi and was proficient enough with fūinjutsu to seal the Nine-Tails within herself. Also, due to being a member of the Uzumaki clan, Mito had an exceptionally long life. Like Naruto, Mito also had the ability to sense negative emotions due to her control over the Nine-Tails.

Quotes

 * (To Kushina)
 * (To Nine-Tailed Kurama) "If you use your power, only hatred will come from it. Stay tranquil deep inside me."