Recruit from the Nest of Maggots

Recruit from the Nest of Maggots is an event where Captain Kisuke Urahara recruits Mayuri Kurotsuchi as part of his plans to establish the Shinigami Research and Development Institute and make the 12th Division his own. During this, other events involving Kaien Shiba, Byakuya Kuchiki, and Gin Ichimaru occur.

Prelude
The day before, Kisuke Urahara is formally promoted as the new captain of the Twelfth Division. As Urahara greets his new division, Hiyori expresses her difficulty and refusal to accept Urahara as the new captain. The following morning, Hiyori discovers that Urahara has remodelled the captain's office, installing large pieces of equipment to the room. She becomes angry with him, noting how different it is. Urahara replies that it is his room now and says that they should try to get to know each other, bit by bit. Hiyori refuses and punches him in the face. Urahara pays it no mind and asks her to accompany him to the Nest of Maggots.

In the Second Division's headquarters, a member of the Onmitsukidō reports that Urahara wishes to enter their grounds, claiming to have already received permission from Yoruichi. Despite not remembering granting such permission, Yoruichi tells him to let Urahara go wherever he wished, despite a protest from Suì-Fēng.

Descent into the Nest of Maggots
As the gates open, Urahara drags the uncooperative Hiyori by the collar of her uniform. It is explained that the Onmitsukidō was originally a separate organization to the Gotei 13. However, when the head of the unit becomes a captain as well, the two units become closely linked. Under Yoruichi's leadership, the commanders of each of the five sections of the Onmitsukidō are seated officers in the Second Division. Urahara tells Hiyori that as the Second Division's Third Seat, he was the head of the Detention Unit. He explains the main duty of the Detention Unit was guarding those who had committed crimes in Seireitei. Hiyori notices his use of the "main" and asks what other duties the unit had. Kisuke tells her that the Detention Unit also investigated and detained any Shinigami who was deemed to be a potential threat to other Shinigami or might impede the duties of their Division. Such people were locked up in an underground facility in the Second Division's grounds that is known as the Nest of Maggots.

As they descend into the cave, Hiyori asks if people are really locked up in such a place. Urahara replies that it is a horrible affair, but it is not quite a prison. While the detainees cannot leave, their movements are not restricted within the facility. When Kisuke warns her that someone might suddenly attack her, she asks what they have done. Urahara tells her that they have not actually done anything wrong, but have simply been deemed to be dangerous elements according Seireitei's regulations. Hiyori criticises this, but is interrupted by Urahara, who asks her if she knew any Shinigami who has withdrawn from the Gotei 13. He explains that there is no such thing as “withdrawal.” He tells her if somebody has to leave the Gotei 13 due to personal circumstances, it is called a "leave of absence." If that leave of absence prolongs and it is unlikely the person will come back, it results in "Decommissioning." Actual withdrawal from the Gotei 13 of the member’s own volition is not accepted. Instead, “withdrawal” is a cover that means the Shinigami has been forcibly transferred to the Nest of Maggots. This is all in accordance with the views of the Central 46. Urahara tells Hiyori that he has always had something on his mind ever since he took command of the Detention Unit. He notes that he has thought that even though the people kept in Special Detention are considered possibly dangerous, they might be able to turn their dangerous potential into assets if they were given a suitable environment in which to work. Hiyori is then attacked by a detainee and instinctively reaches for her sword. As she recalls that she did not have her blade, Urahara protects her from the attacker and apologizes for not reminding her that she did not bring her Zanpakutō. He states that the Nest of Maggots forbids bringing any weapons into the facility. As such, all Detention Unit leaders must be capable of subduing any detainee with their bare hands.

After fending off the attacker, the two go down into a lower level. Urahara then shows Hiyori the only detainee that is placed in a cell, who asks him what business he has here. It is then revealed that the prisoner is Mayuri Kurotsuchi. Urahara tells a shackled Kurotsuchi that he has come to offer him the opportunity to leave. Surprised, Hiyori asks who Kurotsuchi is. In response to Hiyori’s manner of speech, he states that she seems to be a boy with no manners. This angers Hiyori, who calls him a “white dango.” Urahara tells Kurotsuchi that Hiyori is his lieutenant, which prompts Kurotsuchi to congratulate Urahara on his promotion. Urahara thanks him, but goes back to the topic of his proposition as Kurotsuchi has not yet given a reply. Kurotsuchi turns down his offer to leave the Nest of Maggots, and stating that he is satisfied with his life there when asked why by Urahara. When Urahara points out that there is nothing to tinker with in the detention facility, Kurotsuchi asks why he wants to free him. Urahara states that he needs Kurotsuchi’s abilities. Suspicious of him, Kurotsuchi suggests Urahara to stop lying. Urahara brushes off the brazen response, noting how much Kurotsuchi is on guard around him. Despite this suspicion, Kurotsuchi points how he still has difficulty understanding Urahara and how Urahara is a truly unpleasant type of man. Urahara again asserts that he genuinely needs Kurotsuchi’s skills and reveals that he is thinking of creating an organization within the Twelfth Division unlike any organization seen before in Soul Society called the Research and Development Institute. He goes on, saying that he would like Mayuri to be its vice-president. Hiyori is shocked at this, as Mayuri asks if Urahara wants him to work under him. Kisuke confirms this and replies that it is not a bad deals as if he were to die, the organization would be his to do with as he pleases. Kurotsuchi smiles, saying that Urahara truly is an unpleasant sort of man.

Contest between Shunpo Masters


While this goes on, Byakuya Kuchiki is practicing his Zanjutsu skills in the grounds of the Kuchiki Manor. His grandfather, Ginrei Kuchiki arrives and notes how hard Byakuya is working. Byakuya asks his grandfather if he will be staying at the mansion. Ginrei states that he is and tells Byakuya to leave his training session at that for the day because he has a guest. As he wonders who the visitor is, Yoruichi appears beside him. Byakuya immediately attacks her, calling her a demon cat. Yoruichi dodges and laughs, saying that that is no way to greet somebody who has come to play with him. Byakuya responds that since he will be the next head of the Kuchiki house, he did not need to waste time playing. In response, Yoruichi steals his hair tie using Shunpo. Laughing, Yoruichi teases the young Byakuya and says he will never catch her. This incurs Byakuya's wrath. Byakuya uses his own Shunpo to chase after her, which he says is far superior to hers. Ginrei comments that Byakuya would improve greatly if loses his hot-headedness and goes to rest a bit.

The New Lieutenant of the 13th Division and the New 5th Division Officer


Elsewhere, Kaien Shiba is having tea with Captain Jūshirō Ukitake. He repeats to Ukitake that he does not wish to be a lieutenant. Ukitake only smiles, telling him to not say that since he will just disappoint him again. In response, Kaien saying that there are others who deserve to be promoted ahead of him. Noting how Kaien’s attitude is appears to be out of a sense of duty, Ukitake states this is very much like him. Disappointed with his reply, Ukitake turns the conversation to the latest genius to graduate from the Shin'ō Academy since Kaien himself. He says that this boy completed the academy course in just one year. Kaien states that this is quite impressive as Ukitake states that the boy is the same age as Byakuya. Ukitake tells Kaien that he heard the child had a seated officer position reserved for him before he joined the Gotei 13. Trying to act modest, Kaien uses this to try to further support his wish to not be promoted to lieutenant. Kaien then asks what division the young genius was assigned to, Ukitake replies that he is now part of the Fifth Division. Later that evening, Sōsuke Aizen applauds the young Gin Ichimaru’s skills. It is revealed that Gin killed his division's Third Seat. Aizen then asks Gin how did he find the Fifth Division’s Third Seat. Gin simply states that the dead Shinigami was not worth his time, to which Aizen replies he is glad to hear that.

Aftermath
The history of several Shinigami is revealed. Urahara is successfully able to recruit Mayuri Kurotsuchi to be his Third Seat and Vice President of the Shinigami Research and Development Institute as part of his work as the captain of the Twelfth Division. Urahara is also able to establish said organization. Ukitake tries to recruit Kaien Shiba to be the lieutenant of the Thirteenth Division. Gin Ichimaru joins the Fifth Division of the Gotei 13 and is recruited by Sōsuke Aizen.