There are nine Hashira in the Demon Slayer Corps and there is a reason why the number is nine.
What does Hashira mean?
Hashira “柱” literally means pillar. In the Demon Slayer Corps the highest ranked members are called Hashira.
Swordsmen who are of lower rank may be killed at frightening rate, but the Hashira are the ones sustaining the Demon Slayer Corps.Reference: Demon Slayer: Kimetsu no Yaiba Comic, Vol.6, Chapter 45
Why are there nine Hashira?
Nine Hashira appear at the end of Episode 21 of the Tanjiro Kamado Unwavering Resolve Arc and the fact that Giyu Tomioka was the Water Hashira is also revealed here. The insect Hashira Shinobu Kocho attempted to kill Nezuko but Giyu Tomioka prevented this. The Master Kagaya Ubuyashiki decides to hold a Hashira meeting (Chugo Kaigi “柱合会議”) to settle the situation.
Giyu Tomioka already appears in the beginning of the story. The related article is here:
The reason why there are “nine” Hashira is that the Kanji character for Hashira consists of nine strokes.
In Shinto “神道”, one of the religions in Japan, the word Hashira is used to count Gods, e.g. Three Hashira of God.
To know more about Shinto, visit this website: Association of Shinto Shrines
In Japan Head of Family is called Daikokubashira “大黒柱“. The word Hashira is used here as well. So in general Hashira is someone who is respected. This might also be one of the reasons why the word Hashira was selected to express the highest ranked swordsmen.
The Hashira is named as: the name of breathing technique + Hashira. In Episode 21 and 22 of the anime Demon Slayer: Kimetsu no Yaiba, all nine Hashira appear:
|Color of Nichirin Blade
|水柱 The Water Hashira
|蟲柱 The Insect Hashira
|炎柱 The Flame Hashira
|音柱 The Sound Hashira
|恋柱 The Love Hashira
|霞柱 The Mist Hashira
|岩柱 The Rock Hashira
|風柱 The Wind Hashira
|蛇柱 The Snake Hashira
In the past there were also Hashira who used other breathing techniques. Jigoro Kuwajima, who trained Zenitsu Agatsuma was the Thunder Hashira (“鳴柱”). Kanae Kocho, the elder sister of Shinobu Kocho, was using Flower Breathing and was the Flower Hashira (“花柱”).
the Nichirin Blades of the Insect Hashira and the Snake Hashira are “bluish” color, as the Insect Breathing and the Snake Breathing are derived from the Water Breathing.
The breathing techniques are explained in the following article:
Nichirin Blade of Hashira
Nichirin Blade of Hashira has four Kanji characters engraved near the handguard: 悪鬼滅殺. It is pronounced as “Akki Messatsu” and means “Kill evil demons”.
For more explanation on Nichirin Blade, see the related article:
Rank engraved on the back of the hand
In the case of Hashira, how the rank is shown on the back of the hand is also different. Instead of the rank “Hashira (柱)” itself, the name of the breathing technique shows up. For example, the Love Hashira should have the kanji character for “Love (恋)” engraved.
There are nine Hashira, as the Kanji character for Hashira “柱” consists of nine stroke. Everything is considered very well.