Bleach Gotei 13

The Gotei 13  st Division Captain: Yamamoto Genryuusai Shigekuni 1st Division Vice Captain: Unknown 2nd Division Captain: Soi Fong 2nd Division Vice Captain: Ohmaeda Marechiyo 3rd Division Captain: Ichimaru Gin 3rd Division Vice Captain: Kira Izuru 4th Division Captain: Unohana Retsu 4th Division Vice Captain: Kotetsu Isane 5th Division Captain: Aizen Sousuke 5th Division Vice Captain: Hinamori Momo 6th Division Captain: Kuchiki Byakuya 6th Division Vice Captain: Abarai Renji 7th Division Captain: Komamura Sajin 7th Division Vice Captain: Iba Tetsuzaemo

8th Division Captain: Kyouraku Shunsui 8th Division Vice Captain: Ise Nanao 9th Division Captain: Tousen Kaname 9th Division Vice Captain: Hisagi Shuuhei 10th Division Captain: Hitsugaya Toushiro 10th Division Vice Captain: Matsumoto Rangiku 11th Division Captain: Zaraki Kenpachi 11th Division Vice Captain: Kusajishi Yachiru 12th Division Captain: Kurotsuchi Mayuri 12th Division Vice Captain: Kurotsuchi Nemu 13th Division Captain: Ukitake Juushiro 13th Division Vice Captain: Shiba Kaien (deceased) Former 2nd Divison Captain: Shihouin Yoruichi Former 12th Divison Captain Urahara Kisuke Current 13th Division, 3rd Seat Kotsubaki Sentaro & Kotetsu Kiyone

1st Division Captain: Yamamoto Genryuusai Shigekuni

First Division Captain and founder of the shinigami academy. By virtue of his position and seniority, he is also the supreme commander of the Gotei 13.
Yamamoto-taicho looks like a very old man, almost after the fashion of the Taoist Immortals, but under his shinigami robes he still has a strong body that has not decayed with age. His spiritual pressure is possibly greater than any other being in Soul Society; it was enough to paralyze Ise Nanao--the Eighth Division Vice-Captain--with a mere glance. He wields Ryuujin Jakka, the strongest of all fire-type zanpaku-to. His skill in kidou is unknown, but probably as formidable as his swordsmanship, as he appears to embody the convention of the "old master."
Kyouraku Shunsui (8th Division Captain) and Ukitake Juushiro (13th Division Captain) seem to have a particularly strong relationship with Yamamoto-taicho. He mentions that they were the first graduates of his shinigami academy to rise to the rank of captain, and some clips from the anime show Yamamoto-taicho sparring with the two (and easily winning).

1st Division Vice Captain: Unknown

Not much is known about this man, other than his outfit, which is somewhat different and more formal than those of the other vice-captains. Judging from his appearance, face, and weapon, it is probably a safe guess that he is a sophisticated sort of man.

2nd Division Captain: Soi Fong

Captain of the Second Division, and Commander of Covert Operations and Executive Militia.
Not much is known about Soi Fong. She is from a lower noble that served the great Shihounin family, and became a comrade of Shihouin Yoruichi (former Captain of the Second Division) at a young age.
In combat, Soi Fong wields Suzumebachi, one of the more unique Zanpaku-to. She also seems to have the entire Covert Operations division at her beck and call, ready to fight at a moment's notice.

2nd Division Vice Captain: Ohmaeda Marechiyo

Descended from one of the noble families in Soul Society. Omaeda is an enormous individual, dwarfing his petite Captain. He is also her opposite in personality, being rather a buffon and not especially bright. Not much else is known about him.

3rd Division Captain: Ichimaru Gin

The sly-faced, perpetually smiling Ichimaru seems to be almost totally amoral, willing to injure even his own comrades if it helps him get what he wants.
Ichimaru's personality is inscrutable. It is impossible to tell if his ever-present grin is merely a facade to hide his true thoughts, or if he really does take devilish glee in the various tragedies he sets in motion.
As with most captains, Ichimaru's past is shrouded in mystery. However, he seems to have a rather strong relationship with vice-captain Matsumoto, who is probably his only true friend.
Ichimaru's zanpaku-to is Shinsou, which he uses with impressive skill, if rather indiscriminately.

3rd Division Vice Captain: Kira Izuru

A thin and somewhat neurotic individual, Kira is good friends with fellow vice-captains Hinamori and Abarai. He seems a decent enough sort, but is also extremely loyal to his captain, Ichimaru Gin. This sometimes puts him in difficult positions, where he is forced to choose between loyalty to his captain and loyalty to his friends.

4th Division Captain: Unohana Retsu

A kind and peaceful woman, who is perfectly suited to be Captain of the healing-oriented Fourth Division. She seems willing to help almost anyone in need, but don't let her motherly appearance fool you; she is highly intelligent and possesses an extremely strong will.
Though possessed of a compassionate personality, Unohana ultimately remains loyal to the core principles of the Gotei 13 and Yamamoto Genryuusai, even at times when she seemingly feels that official policy is not the right course of action.
She has not engaged in any combat to date, but wields the healing zanpaku-to Minazuki as her blade of choice.

4th Division Vice Captain: Kotetsu Isane

As kind-hearted and mild as one would expect from the Fourth Division, but seemingly having a slightly more combative nature. She is extremely loyal to her captain, whom she idolizes, and has a sister (Kiyone) who is ranked as third seat of the Thirteenth Division. Not much else is known about her.

5th Division Captain: Aizen Sousuke

Captain of the Fifth Division. A rather unassuming individual, but one with great depth. Sousuke is a brilliant thinker and fighter--probably the second most powerful captain after Yamamoto--and is respected among shinigami for his chivalrous demeanour. He seems to be wary of Ichimaru Gin and his motives.
He acts gently toward his subordinates, particularly Hinamori Momo, his vice-captain. He recognizes the respect she has for him, and plays along with her hero-worshipping.
His zanpaku-to is the amazingly devious and powerful Kyouka Suigetsu.

5th Division Vice Captain: Hinamori Momo

A sweet, gentle, and somewhat naive girl who seems entirely unsuited to be a vice-captain in the rough and dangerous world of Soul Society. Despite her cute and innocent appearance and demenour, however, she can cross swords with the best of them, and is an accomplished master of kidou.
She has idolized Aizen Sousuke since before she became his vice-captain, and holds an almost unhealthy degree of loyalty to him, particularly in times of extreme emotion.
Hinamori's best friend, however, is Hitsugaya Toushirou, captain of the Tenth Division (whom she calls "Shiro-chan" for short, much to Hitsugaya's annoyance). They have known each other since before they were shinigami, and she seems to love him as though he were her younger brother.

6th Division Captain: Kuchiki Byakuya

Captain of the Sixth Division. Byakuya is head of the noble Kuchiki family, and as such is sophisticated in his philosophy and manner of speech. He is perpetually cool and collected--many might say cold and emotionless--having never been seen to either smile or lose his temper.
Despite his youthful appearance, Byakuya is actually a widower. His wife died some years ago, seemingly of one or another illness. It is not known whether Byakuya's reserved personality developed or increased after his wife's death, but it seems a logical assumption.
He is Kuchiki Rukia's adoptive brother, but does not appear to possess or display much filial affection. Rukia even goes so far as to say at one point that Byakuya never once cared for her in the slightest. This may be a somewhat unfair portrayal, however, as Byakuya seems to be the type who keeps his cards close to his chest, so to speak.
His weapon is the deadly Senbon Zakura, which he wields with suitable elegance to dispatch his foes.

6th Division Vice Captain: Abarai Renji

The personification of "attitude." Renji is almost the exact opposite of his captain, cocky, easily riled, and unsophisticated in his approach. He does not outwardly seem to have much respect for Byakuya, but in reality Renji greatly respects and fears him. It is his dream to one day surpass his captain, and he trains toward this end with almost fanatical fervour.
Renji is friends with Kira and Rukia, with whom he attended the shinigami academy. He bears particular affection--and possibly something a bit more--for Rukia, and he is pained to see her sentenced to death. Though he initially goes along with the orders of Soul Society, Renji grows increasingly resistant as time passes to a course of action he sees as morally reprehensible.

7th Division Captain: Komamura Sajin

The huge Captain of the Seventh Division. Komamura is a mysterious individual, hiding his features from view with a large helmet. He has a great sense of honour, being particularly devoted to Yamamoto Genryuusai. He is close friends with Tousen Kanamae of the Ninth Division. They share similar life philosophies, though Komamura is seemingly less gentle or hesistant in his approach than Tousen.
When it comes time to fight, Komamura wields the niftily named Tengen, a blade with size to match his own.

7th Division Vice Captain: Iba Tetsuzaemo

A former member of the Eleventh Division, plainly evidenced by his continued love of fighting. Tetsuzaemon is the very image of a yakuza, with garish tattoos and a tanto (dagger) zanpaku-to secreted in his kimono. He still maintains good ties with the Eleventh Division, particularly with his old friend Madarame Ikkaku, though it is implied that Tetsuzaemon left the Eleventh in order to advance himself more quickly (which naturally caused some bad feelings with his former Division). Tetsuzaemon is a talented combatant and a master drinker.

8th Division Captain: Kyouraku Shunsui

The creatively dressed Eighth Division Captain. As his overcoat, hat, and stubble might indicate, Shunsui is someone who lives life in a carefree manner. He loves to nap, joke, drink, and generally be laid-back about everything that comes his way. When things get serious, however, Shunsui shows that beneath his whimsical exterior lies intelligence, skill, and a sensitive and compassionate character that hates to watch suffering.
Shunsui has an excellent relationship with his vice-captain (if somewhat love-hate on her part), and is also good friends with Thirteenth Division Captain Ukitake Juushiro, who, along with Shunsui himself, was one of the first graduates of Yamamoto Genryuusai's shinigami academy. It seems that Shunsui also has a good relation with Yamamoto, having coined the nickname "Yama-jii."
When Shunsui is forced to fight, he wields the twin-blade zanpaku-to Katen Kyoukotsu with awesome skill.

8th Division Vice Captain: Ise Nanao

A careful analysis of Nanao-chan (as Shunsui calls her) will reveal that she shares much in common with her captain, such as intelligence, compassion, and sensitivity. What distinguishes them, however, is that Nanao is disciplined and businesslike, in stark contrast to Shunsui's often-lazy attitude. As such, she is the discipline and perhaps even the brains of the Eighth Division, working tirelessly to keep afairs in order and patiently enduring Shunsui's endless flirting and drinking. Nanao has a classic strict librarian's personality, complete with glasses and enormous tome.
Despite her common annoyance with her captain, Nanao actually has quite a good relationship with her superior, and the two truly seem to care for each other. She also does not seem to be averse to the occasional social event herself, though one would imagine that she partakes of parties in strict moderation.

9th Division Captain: Tousen Kaname

The blind Captain of the Ninth Division. Despite his disability, Tousen is a capable fighter with a strong sense of justice. He is also a staunch advocate of taking the path that leads to the least amount of violence. This outlook is shared by his good friend Komamura Saijin. Tousen is, therefore, highly suspicious of Zaraki Kenpachi and the battle-loving Eleventh Division, which he believes may one day plunge Soul Society into bloody chaos.
When the situation demands it, he wields the powerful Suzumushi with skill that belies his blindness.

9th Division Vice Captain: Hisagi Shuuhei

Brave and talented, if a bit rough around the edges. Shuuhei was a top-level student at the shinigami academy, being offered a ranked spot in the Gotei 13 before he even graduated. His courage was emphasized when a training raid he led as an upperclassman (including Renji, Rukia, and Kira, interestingly) went sour and Shuuhei ordered the rest of the trainees to flee while he attempted to hold several powerful Hollows off.

10th Division Captain: Hitsugaya Toushiro

The Tenth Division Captain is the youngest captain in the Gotei 13 by a considerable margin. He is known as a prodigy in study of the shinigami arts, earning him the nickname of "Tensai," or "Genius."
Despite his youth, Hitsugaya is one of the more mature captains, level-headed and perceptive, if a bit lacking in the humour department. Unlike the unemotional Kuchiki Byakuya, however, the right set of circumstances will put Hitsugaya into anger, annoyance, etc.
Hitsugaya seems to get along well with just about everyone except Ichimaru Gin, whom he mistrusts. He has a particularly strong relationship with Hinamori Momo, and also has a strong bond with his vice-captain, Matsumoto Rangiku.
When battle comes around, Hitsugaya wields Hyourinmaru, the most powerful ice-type zanpaku-to in Soul Society.

10th Division Vice Captain: Matsumoto Rangiku

Though most folks probably know her best by her ample... *assets,* Matsumoto is actually quite a capable and loyal vice-captain (if a bit on the lazy side). She has a good relationship with her captain, who--despite his seeming annoyance at her sleeping on the couch during working hours--holds great respect and even admiration for her.
Matsumoto also has the unique (and perhaps dubious) honour of calling Ichimaru Gin a friend. As far as can be determined, she is Gin's only friend, having met long ago while she was training her spiritual energy. She seems to like Gin quite a bit (perhaps in an unrequited manner), and is the only person whom Gin seems unwilling to interfere with.

11th Division Captain: Zaraki Kenpachi

The bloodthirsty Eleventh Division Captain. Zaraki lives for one purpose and one purpose only: to fight. All other concerns are basically secondary. Though Zaraki enjoys fighting with all his strength, he does not seem particularly concerned with winning or losing; the joy of battle is all that matters to him.
Zaraki was originally a nameless swordsman fighting for his life on an apparently daily basis. After much trial, he was spotted by the shinigami and given a position in the Gotei 13, where he rose in the ranks until finally defeating (and, incidentally, killing) the previous Eleventh Division Captain in single combat.
That's not to say that Zaraki doesn't have a softer side, though. He has an unlikely friendship in Kusajishi Yachiru, whose tiny, cute appearance and saccharine personality stand in stark contrast with Zaraki's massive physique and gruff manner. The two are inseperable, however, like father and daughter, and it's safe to say that Yachiru is the only person whom Zaraki's wrath has no chance of touching.
Wielder of a nameless blade, Zaraki is the only captain in Soul Society who does not know the name of his zanpaku-to; this is a testament to his terrifying strength in combat and colossal spiritual pressure.

11th Division Vice Captain: Kusajishi Yachiru

Cotton candy to her captain's tiger, Yachiru seems distinctly out-of-place in the battle-loving Eleventh Division. She is consistently sweet and cute, somewhat airheaded, and totally devoted to her captain (as well as the only person in the world who can get away with calling him "Ken-chan").
Yachiru's perpetually happy personality is well-established; in her infancy, as a nameless orphan, she was quite bubbly and cheerful even among a pile of corpses, where Zaraki found her and named her. Since then, she has accompanied him wherever he goes, gleefully misleading him with her rather bad sense of direction and generally adding a splash of colour to Zaraki's otherwise dark life.

12th Division Captain: Kurotsuchi Mayuri

The epitome of a mad scientist, and hence perfect for the job of Twelfth Division Captain. Mayuri paints himself black and white, wears a strange hat, and has altered his body to grant it many strange abilities. His main goal appears to be pursuit of forbidden knowledge at any cost, and he does not hesitate to resort to sadistic or underhanded methods to achieve his ends. Life means nothing to him; he would turn his own men into living bombs if it meant he could do or learn something more easily.
Though Mayuri is completely cold and cruel to everyone he meets, he does have one loyal supporter in the form of his "daughter," Nemu. She is completely devoted to her master, uncomplainingly taking all manner of abuse and even wishing against his death.
On the frequent occasions when Mayuri wants to fight or perhaps revel in a bit of sadism, he wields the bizarre but lethal Ashisogi Jizou.

12th Division Vice Captain: Kurotsuchi Nemu

Kurotsuchi Mayuri's "daughter," created by the Twelfth Division Captain to be his loyal servant. Despite being constantly mistreated by her "father," Nemu remains totally obedient, loyal, and devoted to his goals. She is not, however, a fool, or someone to be taken lightly.

13th Division Captain: Ukitake Juushiro

The Captain of the Thirteenth Division, with an almost legendary reputation for being a nice guy. Sadly, Ukitake has frail health and is ill a lot of the time, but in his better moments he is a strong and reliable fighter as well as a caring and compassionate leader.
His best friend seems to be Shunsui, with whom he was a fellow student in the early days of Yamamoto Genryuusai's shinigami academy. However, the entire Thirteenth Division seems to love and respect their captain with almost fanatical fervour, and he may thus be said to be a friend of all his subordinates, though not notably close to any of them. Of course, as Kuchiki Rukia's former captain, he is quite concerned as to her eventual fate.
On the rare occasions when he is both in good health and inclined to fight, Ukitake wields Sougyo no Kotowari, one of only two twin-bladed zanpaku-to in all Soul Society.

13th Division Vice Captain: Shiba Kaien (deceased)

The deceased vice-captain of the Thirteenth Division. He bears a strong resemblance to Kurosaki Ichigo, and was apparently a good friend of Rukia's.

Former 2nd Divison Captain: Shihouin Yoruichi

Former Captain of the Second Division. Born into the noble Shihouin family, Yoruichi quickly rose to the rank of captain, and was apparently quite talented at the job.
However, the day came when Urahara Kisuke was exiled, which prompted Yoruichi to help him and follow him to the mortal world. She has since stayed near Urahara, though in the form of a black cat (this seems to be a unique talent of hers).
Yoruichi is smart, sarcastic, and extremely confident, bordering on arrogance. She does not hesitate to show off her impressive talents (nor apparently her impressive body, at least to Ichigo). However, she is quite well aware of her limitations, and is content to retreat to gain a tactical advantage.
She does not seem to wield a zanpaku-to (circumstantial evidence suggests that Soi Fong's Suzumebachi was once Yoruichi's), but her talent in combat is impressive. She has mastered kidou, and is possibly the most talented practitioner of shunpo in history. These combine to make her a lethal opponent easily capable of taking on a captain-class enemy, even without a zanpaku-to.

Former 12th Divison Captain: Urahara Kisuke

The eccentric proprietor of the Urahara Shop, and a man shrouded in mystery. He's always carefree and witty, but also seems to always know just a bit more than he's telling you.
As it turns out, of course, he's the former Captain of the Twelfth Division. For creation of an untraceable gigai that leeches shinigami powers, he was exiled at some point, and forever banned from re-entering Soul Society. (Why this ban was not also placed on his accomplices--which seem to be Yoruichi and Isshin--is a matter of some debate.)
Urahara has an excellent relationship with Shihouin Yoruichi, who is said to be his only living relative. They act a bit like brother and sister, trading playful banter as well as more serious discussion with equal aplomb. There are also a few non-Shinigami who name Urahara as a friend, such as Tessai, Ururu, and Jin.
Though almost always toting it around it its cane form, Urahara is masterful in the use of his zanpaku-to, Benihime.

Current 13th Division, 3rd Seat: Kotsubaki Sentaro & Kotetsu Kiyone

Two nutty and fiercely competitive shinigami. Since the Thirteenth Division is presently without a vice-captain, Sentaro and Kiyone fill the role of second-in-command until a replacement is selected. Both of them quite obviously have their eye on the vice-captain's seat, and to this end constantly try to prove their worth in the eyes of their captain. Their arguing and pomposity tends to make them look more silly than competent, however.
Despite their rather ridiculous actions and personalities, the two third seats, like the rest of the Thirteenth Division, are deeply devoted to their captain and would probably follow him through Hell and back again if he asked them to.