Kakushi

The Kakushi are a brigade of people who work as attendants to the Demon Slayer Corps.

Overview
The Kakushi are a brigade responsible for different tasks, which can range from providing services to Corps members to cleaning up the battlefield after Demon attacks.

Other tasks performed by the Kakushi include:
 * Serving as attendants of the Butterfly Mansion, where they provide aid to the manor's residents and those healing on the premises.
 * Cleaning the mess often left behind after a large battle.
 * Sewing and repairing the uniforms Demon Slayers wear.
 * Transporting people to and from the Swordsmith Village.

In some cases, Kakushi are Demon Slayers who have been injured and retire from being Demon Slayers. There are also individuals who failed to pass the Final Selection examination but become Kakushi in order to still be of use to the Demon Slayer Corps.

Attire
They wear black versions of the standard Demon Slayer uniforms consisting of a gakuran jacket and hakama pants. To protect their identity, they wear black head coverings with white linings, and a paper-like mask is tied around their face, divided in two sections, one in the front and the back, left to hang freely to allow them to speak and breath easily, which is distinctive for its three wide lines covering the expanse of the fabric.

Trivia

 * The kanji used for the brigade's name means "hidden"(隠)(kakushi). Other meanings include "conceal", "invisible", "pity", "sympathize", which overall reflects the nature of their work: They're the hidden support of the Corps, always working tirelessly behind the scenes to ensure that slayers can keep fighting in the frontlines and are often the ones to comfort the grieving people who lost their loved ones during a Demon attack.
 * It has been revealed in a Sengoku rumor that the Kakushi were formed in the Sengoku era. After the traitor Michikatsu killed the then-acting leader of the Demon Slayer Corps and took his head to Muzan Kibutsuji, more effort was put into hiding the master's residence. That was also the time when the Kakushi were first formed.