Akatsuki (meaning "Dawn" or "Daybreak") is a fictional criminal organization in the anime and manga series Naruto. It is first introduced midway into the first part of the series, and its members gain significance as the main antagonists during the second part. The organization is composed of some of the most powerful criminals in existence.
Despite being composed of only ten (currently nine) members, Akatsuki is arguably the most powerful organization in the Naruto universe. Each member of Akatsuki is an S-class criminal, feared for their tremendous powers and ruthless nature. The exact criteria for admission into the group are unknown, but extraordinary fighting ability and ruthlessness seem to be prerequisites. Unique traits (genetic or otherwise) also seem to be a common factor among its members. Two of the more prominent members so far, Itachi and Sasori, both undertook some sort of challenging task at the time of their entering the group. Sasori mentions during his fight with Chiyo and Sakura that "[he] hadn't had this much difficulty since joining Akatsuki." Itachi was responsible for murdering his whole clan (save for his little brother, Sasuke) around the time he is believed to have entered, but it can't be said for certain that the two events were linked.
Akatsuki doesn't seem to have any strict organizational structure, though its members do maintain several unique practices. They rarely seem to meet in person, instead communicating through telepathy and astral projection when necessary. When their entire group is introduced at the end of the first part of the series, one member notes that it had been seven years since they had all been together in such a fashion. Their meetings are much more frequent in the second part of the series due to their increased activity. The members of Akatsuki seem to have little consistency in their individual goals. They only group together because Akatsuki's overall goal in some way benefits the individual goals of its members. Akatsuki members don't particularly value the lives of their comrades, either; a member's death in itself will not bother the other members, but rather the fact that someone was able to kill that member.
Akatsuki's overall goal is world domination. To achieve that goal, the leader has set up a three-step process to work their way to it. First, they plan to obtain a large amount of money to support their organization. Second, they plan to set up a mercenary group loyal to no village. To build their reputation, they plan to accept any mission below the usual cost, which is covered by the excess amount of funds earned in the first part of their plan. Because there haven't been any wars in some time, the established shinobi villages can't afford to charge such low prices, leading the smaller countries to hire Akatsuki over the more expensive shinobi villages. By using the tailed beasts, Akatsuki can start wars and then immediately quell them, solidifying their reputation and convincing every country to depend on them, thus cornering the market in shinobi labor. Without any business, the other shinobi villages will collapse due to a lack of funds. Finally, after Akatsuki is the only major force of shinobi in existence, they can easily conquer the other countries.
As a large part of their plan, they actively hunt the tailed beasts and their hosts. Once a tailed beast or its host is captured, they seal them in a large statue for use at a later time. Akatsuki possesses six tailed beasts: the one-tailed Shukaku, the two-tailed demon cat, the three-tailed demon, and three other unknown demons.
Akatsuki originally had ten members, but they are currently at nine following the defection of Orochimaru. Only one member, Sasori, has died, and Tobi, a former subordinate of the group, quickly assumed his position. Orochimaru, however, has yet to be replaced, despite having left the group several years before its initial introduction; this is likely because Orochimaru took his Akatsuki ring with him when he left.
Though all of the members have been shown to some degree, two have yet to be named. The first has had some dialogue and been attributed to being the leader, while the identity of the other remains a complete mystery. In the anime, only Kisame and Itachi have been named, though Zetsu made an appearance at the end of the battle between Naruto and Sasuke. Several of the members also have short speaking appearances near the end of episode 135.
Akatsuki members usually work in teams of two. Teams are built to complement each other's abilities and talents to create a formidable duo. For example, Hidan and Kakuzu both use their immortality to their advantage by using attacks that indiscriminately destroy everything in their path. Due to Orochimaru's defection, their numbers are now uneven, so one or more members appear to be working alone. Currently, Zetsu, the leader, and the unnamed member are not known to be on any team. Each member thus far has shown at least a working loyalty to each other and their mysterious leader, and they have excellent working relationships. On a personal level, however, many of the team members exhibit outright animosity towards one another, though they do not let it get in the way of their missions.
Each Akatsuki member wears a single, unique ring, and no two members wear a ring on the same finger. Each member wears their ring on the same finger as the spot they occupy on the giant statue. In total, there are ten rings, but Akatsuki only possesses nine; Orochimaru kept the tenth after he defected from the organization. It still rests on the little finger of the severed left hand from his original body. The rings seem to have some special significance; Tobi believed that he could become a member after finding Sasori's ring, and although Zetsu claims it's not as easy as that, Tobi does indeed become a member. Deidara reinforces the significance of the rings after losing both his arms by expressing more concern for finding the arm with his ring, rather than finding the arm itself. Each ring bears a unique symbol, the first kanji of its name.
Tailed beast extraction
Whenever an Akatsuki member captures a tailed beast or its host, it is taken to their lair. Once there, the Akatsuki leader summons a giant statue of a humanoid monster. The leader doesn't need to be present to summon the statue, nor do Akatsuki members need to be physically present for the statue to activate. Any Akatsuki members unable to reach the statue can use astral projection to appear at the statue. The statue itself seems to symbolize restriction or sealing. The creature's hands are handcuffed, its eyes are blindfolded, and a bit is in its mouth, which falls out when the Akatsuki members are sealing a tailed beast. On the creature's blindfold are nine closed eyes (eight eyes in two rows of four with the larger ninth eye in the center), each corresponding to one of the nine tailed beasts. The eyes don't appear to be in any specific order, as the eye representing the one-tailed Shukaku is the second on the upper row while the eye representing the three-tailed beast is the third on the lower row.
After the summoning, the host or tailed beast (depending on if it is sealed in a person or not) is placed in front of the statue while each Akatsuki member stands on the finger that corresponds to their specific ring. The members then perform Sealing Technique: Illusionary Dragon Nine Consuming Seals to draw the spirit of the beast (or the beast itself) into the statue. Once the beast is sealed, all the eyes open, and the pupil of the eye that corresponds to the beast appears, indicating that it has been successfully sealed. It's unknown if the statue serves any other purpose than to contain the captured tailed beasts.