Hashira

The Pillars are the top-ranked and most powerful swordsmen among the Demon Hunters that serve as the Demon Killing Corps' elite warriors.

Overview
The Pillars are the nine most powerful swordsmen among the Demon Hunters who sustain the Demon Killing Corps. Those who are of lower rank may be killed at a freighting rate, as each Pillar possesses a distinct breath style which is learned from a cultivator or developed through extreme training. The group is overseen by the leader of Demon Killing Corps Ubuyashiki Kagaya.

Pillars are constantly searching for a Tsuguko (Successor), that can take their place when they die or retire. Each Pillar is assigned to a specific region that they need to protect. They also need to gather information about demons and improve their own swordsmanship, because of their busy schedule, they usually would only train their Tsuguko. To become a Tsuguko, you either apply and a Pillar accepts or you get scouted by him. Being of the same Breath Style helps, but a Pillar still can take a successor with different Breath Style.

The time needed to become a Pillar though hard training is usually 5 years for normal people, but talented and fast learners can do it in 2 years. To become a Pillar, you will also need to defeat one of the Twelve Demon Moons or 50 demons. Swordsmen who can use the breaths of flames and water have become Pillars in every era, no exceptions.

History
After the fight with Lower Moon One, Enmu, the Upper Moon Three, Akaza, showed up. A fight between Akaza and Rengoku Kyoujurou occurred. As a result of the fight, Akaza fled, but Kyoujurou died from his wounds and left a vacant Pillar spot.

Not long after that, Tengen Uzui took Tanjirou Kamado and his group to a mission in the Red Light District. There, they encountered Upper Moon Six, Gyuutarou & Daki. As a result of their fight, Gyuutarou and Daki died, and Uzui lost his left eye and left arm, forcing him to retire and leave a second vacant Pillar spot.