Insignia

The thirteen divisions' insignias.Each of the 13 divisions in Gotei 13 have their own symbol that represents the division's primary role, which all seem to be based on flowers. When a power limit is placed on a captain or lieutenant, their symbol appears on a certain part of their body until the limit is lifted. Each symbol also has a specific meaning, but not all of them have been revealed. The 11th Division symbol means 'fight' while the camellia symbol of the 6th Division means 'noble reasoning'.

Uniforms

A captain's uniform. This one in particular is worn by Gin Ichimaru.Most Gotei 13 personnel wear the standard shinigami uniform, called shihakushō (死覇装, lit. garment of dead souls?) - a white kosode, a black kimono and hakama, and a white obi sash. Lieutenants sometimes also wear an armband which carries their division symbol and its number, usually on their left arm. They are required to do this when they are summoned to a meeting but apart from this it seems that it is rarely compulsory; at the time the series takes place, the use of the armbands was noted to have fallen out of fashion.

Captains wear a white haori over the usual black shinigami clothes, with the number of their division on the back, inside the Gotei 13 symbol (a rhombus). The Captain's Haori comes in two styles: sleeve and no sleeve. Gotei 13 officers, particularly captains and lieutenants, often customize their personal appearance or that of their uniform. Some of these modifications include:

Captain Soifon of the 2nd Division wears a sleeveless and backless shinigami outfit (when she's fighting) under her haori, which is standard issue for the head of the special forces. She also wears a yellow sash a layer above, but slightly lower than her white one.

Captain Retsu Unohana of the 4th Division wears an obi sash rather than a standard one.

Captain Byakuya Kuchiki of the 6th Division wears an extremely expensive scarf named ginpaku kazahana no uzuginu and a white ceremonial hairpiece symbolizing his noble lineage.

Captain Sajin Komamura of the 7th Division wears shoulder guards over his haori and large gloves which goes up to his arms. He also wore a helmet to hide his appearance. He later removed the helmet.

Captain Shunsui Kyōraku of the 8th Division is probably the most flamboyantly dressed of the captains, always seen wearing a straw hat and a gaudily-colored haori over his uniform.

Captain Kaname Tōsen formerly of the 9th Division wears an orange scarf with his outfit, a sleeveless keikogi as well as white boots.

Captain Toshiro Hitsugaya of the 10th Division wears a green sash pinned with a star around his shoulder to hold his sword.

Captain Kenpachi Zaraki of the 11th Division wears a shredded edged (from combat) haori, which was taken from the previous captain.

Captain Mayuri Kurotsuchi of the 12th Division wears a bloated purple cravat and a hat decorated with two horizontal spikes.

Lieutenant Chōjirō Sasakibe of the 1st Division wears a jinbaori over his shihakushō.

Lieutenant Shūhei Hisagi of the 9th Division wears a sleeveless keikogi and black choker.

Lieutenant Rangiku Matsumoto of the 10th Division wears a top that is deliberately loose and hangs open to reveal her ample bosom. She also wears a pink scarf (or stole), and wears her lieutenant's badge around her waist with her sash, tied in a bow.

Lieutenant Nemu Kurotsuchi of the 12th Division has a very abbreviated outfit: the hakama is absent, leaving her with a mini-skirt version of the kimono that is belted at the waist.

All known members of the 9th Division wear keikogi without sleeves, including the captain.

Ranks

Ranks

As with any army, the Gotei 13 has ranks. There are 20 ranks for officers but no ranks for non-officers. The lower the number is, the more important. The ranks and their descriptions are below, from highest to lowest in terms of strength.


Commander-General

The sōtaichō (総隊長, lit. commander-general, dubbed as head-captain) is the leader of the Gotei 13 and the captain of the 1st Division; the implication is that this is an ex officio or a primus inter pares position. The current holder of this title is Shigekuni Yamamoto-Genryūsai.


Unit Commander

A Taichō (隊長, Taichō? lit. Unit Commander), commonly referred to as Captain, are the leaders of the thirteen divisions (with the special case of the Commander-General). While "captain" is not an accurate translation of the rank, it's appropriate considering the size of the unit they lead. A single Gotei 13 'unit' (隊) is estimated at about 200-500 troops. Viz renders the units as 'companies' rather than 'divisions' because captains lead companies in real life. However, given that each Captain in Bleach leads a major part of a military wing or corps, they could be division commanders or Generals. Most literally, the name simply means 'unit commander', which could be practically any officer rank.

Captains are generally the most respected shinigami in Soul Society, with the Central 46 Chambers, Demon Art Corps, and special forces leaders possibly being on equal status. With one exception (Kenpachi Zaraki), all captains are able to perform the bankai of their zanpakutō and are generally much more powerful than even their lieutenants. Knowing the bankai gives captains an average of five to ten times the strength of shinigami who are unable to perform it. They have also extensively trained, if not mastered, their bankai, allowing them to actually use the enormous power effectively in battle. Most captains are also skilled in the use of shunpō, kidō, and generally have excellent knowledge of shinigami history and battle tactics. All of these factors create a huge power-gap between captains and lower-ranked officers.

There are three different ways to become a Gotei 13 captain:

To take the captain proficiency test (隊首, taishu?), which requires the ability to perform the bankai. Presumably, most shinigami become captains using this method. At least three existing captains, including the Commander-General, have to witness the test.
To have personal recommendations from at least six captains and approval from at least three of the remaining seven.
To defeat a captain one-on-one with at least 200 witnesses from the captain's division. Kenpachi Zaraki is the only known captain to have achieved his rank using this method.

Vice-unit commander

Fukutaichō (副隊長, Fukutaichō? lit. Vice-Unit commander), more commonly referred to as Lieutenants, are the 2nd seated officers in each division. Because captain describes the unit commander, vice-captain is the most literally accurate translation some have used. The Viz manga translation renders the rank as the similar but somewhat longer "assistant captain", while the English dub of the anime uses the term "lieutenant". Although this does not apply to modern armies, in historical real-life armies the lieutenant has been the adjutant of the captain, as is the case for fukutaichō and taichō in Bleach. Therefore, lieutenant is a correct real-life equivalent of this rank. Holders of this rank in Gotei 13 have also been called adjutants.

Lieutenants function as executive officers for their division, taking care of or supervising day-to-day operations. They (along with their captains) are not assigned to one specific squad. They generally only know the shikai of their zanpakutō, but are still the second strongest in their division. In the case of a division captain's death, departure, or other circumstances making him unable to perform their duties, the lieutenant acts as the substitute captain until another can be assigned.


Seated officers

Sekikan (席官, Sekikan? lit. Seated officers) are the remainder of the officers in the Gotei 13 who hold ranks at or below 3rd Seat. Captains have the rank of 1st Seat and lieutenants are 2nd Seat. Next to that, there are 18 more seats (3rd to 20th). These ranks are somewhat analogous to junior officers or non-commissioned officers in modern militaries. There seems to be a distinction between senior and junior seated officers, just like in real-life armies. In the Gotei 13, only one person can hold a senior officer rank (such as 3rd or 5th seat), but there are several holders of junior officer ranks (e.g. 20th seat). This may vary from division to division however, as there are two 3rd Seats in the 13th Division. Seated officers often lead subunits within each division (for example, Hanatarō Yamada is leader of 4th Division's 14th Advanced Relief Team).

Gotei 13

The Gotei 13 (護廷十三隊, goteijūsantai, 13 Division Imperial Guards, or 13 Court Guard Squads in the English dubbed version?) is the organization which most shinigami join. It is split into thirteen divisions (hence the name), with several divisions having certain specializations. The 4th Division is the medical/supply division, the 11th Division is the combat division (specialization in swordsmanship), and the 12th Division is the research/scientific division. The 9th Division was shown, in a Shinigami Cup extra, to be in charge of newspaper and magazine-related duties. It's unclear if the other divisions are specialized, as the four above are the only ones who receive any significant attention apart from their members.

Las Noches

Las Noches (虚夜宮（ラス・ノーチェス）, Rasu Nōchesu?, Spanish for "the nights," Japanese for "hollow night palace") is the fortress and base of operations of Sōsuke Aizen, Gin Ichimaru and Kaname Tōsen after their defection from Soul Society. They reside there with their army of arrancar.

Las Noches consists of a main building with a domed center surrounded by several large towers and smaller buildings. Atop the dome are six smaller towers (or as they appear), which seem to contain areas such as Aizen's throne room and the Espada meeting hall. Also, in the room where Orihime Inoue is kept, there is one large Middle-Eastern rug on the ground that is facing outside, much like those in rooms used for Islamic prayer. Like everything else in Hueco Mundo, every building is colored white.

Las Noches is easily the largest building structure in the Bleach universe, appearing as large as (if not larger than) Seireitei in Soul Society. Due to its immense size, Ichigo Kurosaki once commented that it could be an illusion as he, Chad, and Uryū Ishida did not seem to make any progress getting closer to it, despite running until they were exhausted. Also, according to the arrancar Nel Tu, it takes about three days to move around its width.

The inside of the Las Noches' domes are sky blue, which Aaroniero Arruruerie claims were created by Aizen so that the light of the sky would help him observe anywhere he wishes. However, since Aaroniero must stay out of the sunlight to use his abilities, he may simply have lied as an excuse to stay inside. The position of the halls within the palace can also be adjusted, allowing the one operating them to direct the movements of intruders.

Hueco Mundo

Hueco Mundo is located between the human world and Soul Society, though it is separated from the bordering dimension known as the dangai. It can only be accessed by tearing the dimensional fabric separating the worlds, which allows hollows to travel to any other dimension at will. Depending on the hollow, the effect for this varies. Regular hollows usually appear from a small black vortex or form out of smoke, while menos-class hollows quite literally tear the sky apart to emerge. Arrancar use a more stable variant of the latter technique known as garganta.

The landscape of Hueco Mundo is a seemingly never-ending white desert, with dunes like those of the Sahara. The desert is littered with what appear to be boulders and shriveled trees, but these are actually a form of quartz. In the anime, the seemingly small trees are shown to extend far underground, and support the desert above. Hueco Mundo exists in perpetual night, and the Moon is on the opposite lunar phase of that in the human world. Like Soul Society, the atmosphere is filled with spiritual energy, but it is more concentrated, allowing hollows to gain nourishment despite the lack of human souls.

Like that in real world deserts, active life in Hueco Mundo appears to be few and far between. With the exception of the arrancar, most hollows dwell below the surface or in other areas until something provokes them to leave their shelter, like the intrusion of a foreign entity. This is expanded upon in the anime: underneath the desert of Hueco Mundo is a vast cavern called the Menos Forest, where most hollows take refuge. According to the shinigami, all hollows dwell in Hueco Mundo regardless of their shape, size, or power.

In the anime, hollows have also been shown to be able to drag other spirits into Hueco Mundo, as seen with Orihime Inoue's brother, Sora. In this case, Sora was forcefully made into a hollow by several others and sent against Ichigo Kurosaki.

Seireitei

Seireitei (瀞霊廷, lit. court of pure souls) is in the center of Soul Society, a circular shiro with four main entrances, each guarded by a Gate Guardian. The walls are made of Sekiseki, a material known to sap all spiritual and psychic energy when one portion is faced in a particular direction, similar to magnetic lodestones. The deathstone also forms a spherical barrier around the city, preventing anyone from entering anywhere other than the four gates.

The majority of the residents of Seireitei, nobility and shinigami alike, do not interact with the citizens of Rukongai. However, residents of Rukongai, like Renji and Rukia, are allowed to apply for the shinigami academy, which is often the only escape from the poorest conditions of Rukongai. Some Seireitei residents, such as ex-commander of the special forces, Yoruichi Shihouin, and the Shiba clan, do maintain residences outside the castle.

At the center of Seireitei are the Shrine of Penitence (senzaikyū), a white tower, and Sōkyoku (双殛) Hill, where executions take place