Rasa

The was the previous leader of Sunagakure. His real name was Tadashi.

Background
Because the Land of Wind's daimyō cut down Sunagakure's budget and instead used Konohagakure's less expensive services, the Fourth Kazekage saw his own village in danger of extinction. In order to prevent that, he decided to focus on increasing the quality of the ninja in the village. As such, he ordered Chiyo to seal the One-Tailed Shukaku within his youngest son, Gaara, so that he could become Suna's ultimate weapon, at the cost of his wife, Karura's life. He then taught Gaara ninjutsu, but assigned Yashamaru to be Gaara's caretaker ostracising him from his elder siblings Temari and Kankurō.

However, as Gaara grew and his abilities began to manifest, the Fourth realized that this had been a poor choice, and started to view Gaara as a failed experiment that threatened the inhabitants of Suna, due to Gaara's unstable nature of attacking citizens unintentionally. In time, the Fourth began issuing orders for Gaara's assassination, none of which were ever successful. After Yashamaru's failed attempt, and Gaara began to have more control over his powers due to his new ideals of being alone, the Fourth Kazekage learned to appreciate Gaara's usefulness, and stopped issuing attempts on his son's life, in hopes of him becoming a powerful tool.

Personality
Befitting his status and responsibility as leader, the Fourth Kazekage cared deeply about the well-being of his village, so much so that he was willing to ally with Orochimaru to destroy Konohagakure to bring Sunagakure's resources back up, despite knowing Orochimaru is a highly dangerous criminal. This turned out to be a fatal mistake on the Kazekage's behalf, as he and his bodyguards were betrayed and assassinated by Orochimaru.

In his family life, however, the Fourth Kazekage seems to be much more cold and uncaring, as he was fully willing to sacrifice his wife's life to turn his third child into a monster who will be destined to a prejudiced life. When he saw Gaara's lack of control being a danger to the villagers, he blamed the child for it and attempted to have him assassinated, despite it being the father's fault for creating such a monster in the first place. He also spent little time with his son, instead placing him in the care of his brother-in-law.

Abilities
While he is yet to be seen in combat, the fact he was a Kazekage as well as the fact he was placed in a group with the Second Mizukage, Second Tsuchikage and Third Raikage, all of whom were incredibly powerful shinobi, implies that he himself is very powerful. He was shown to be quite observant, pinpointing Gaara's Third Eye that was spying on them after Mū sensed his chakra.

Invasion of Konoha Arc
When Orochimaru approached Sunagakure with the proposition of joining forces in invading Konohagakure, the Fourth Kazekage agreed. With Sunagakure still suffering from the daimyō's budget cuts, the Fourth hoped a successful invasion would prompt additional funding. He planned to have Gaara unleash Shukaku from the center of Konoha during the Chūnin Exams, giving the invaders an advantage from the get-go.

The Fourth, however, would not be able to see his plans through, as Orochimaru killed him by impaling his chest with the Sword of Kusanagi. His guards were killed along with him. He then impersonated the Kazekage until the invasion began, making it easier to control the village. After the failed invasion, Baki and some other Sunagakure ninja found the Fourth Kazekage's and his bodyguards' corpses decomposing out in the desert, their faces stolen. Gaara, whose life was made miserable by his father, would later succeed him and become the Fifth Kazekage.

Shinobi World War Arc
The Fourth Kazekage is resurrected by Kabuto Yakushi, along with other deceased Kage through the Summoning: Impure World Resurrection technique, in preparation for the Fourth Shinobi World War.

When Mū, despite his camouflage, is detected approaching the Fourth Division, Kabuto has him summon three other Kage in order to provide support. Amongst this number is the Fourth Kazekage who, during the conversation between the Second Tsuchikage and Second Mizukage, divulged that he was only aware of their exploits due to his elders. He then asserted that although the Second Hokage had died many, many years before his own lifetime, the wretched ability that resurrected them was possessed by another shinobi, named Orochimaru. While the other Kage discussed their desires to fight each other, the Fourth Kazekage noticed his son's Third Eye observing them from afar.

Trivia

 * His hair colour was a dull purple colour in his first appearance, but it is brownish in other appearances.