IU

IU is an A-Class national secret in England and an I-Class State Secret in Japan. If the authorities gained knowledge of your involvement in IU or even just knowing about them, you will be pursued by Public Division 0 or an Armed Prosecutor since merely knowing about IU may put one's life in jeopardy.

Organization Culture
In IU, everyone is a teacher and at the same time, a student as well. It is a place where prodigies congregate, and share their skills with one another, extending their limits further. Infighting within IU may be common since they do not prohibit it within their organization. From what little that has been told and shown.

IU appears to be an amoral secret society whose goal is to continually push, and eventually surpass, the limits of human evolution. The members of the society are usually free to pursue whatever methods they feel are most effective, but all members must defer to the society's senior leaders. Examples of such different methods include the coercion of powerful humans into serving as pawns or members for IU and genetic experiments with the goal of improving the human condition. It is possible that IU ultimately aims to create a superior being comparable to a deity.

Location
IU is headquartered in a 300 meter long Russian Nuclear Submarine, "Vostok." Originally belonging to the Soviet Navy, it was stolen by Sherlock Holmes sometime after the second World War. The name IU is derived from codenames submarines had during the war: It is also said IU poses the capability to destroy any country without being noticed..
 * I: The Imperial Japanese Navy's designation for a submarine.
 * U: The Kriegsmarine, or WWII-era German Navy, designation for a submarine.

History
IU had operations involving or connected to other organization such as, Ranpan, Ulus Tribe, Regiment Hex, Vatican, and Kinokuni. As revealed by Akari Mamiya, IU assaulted her family's household killing many and forcing the survivors to go into hiding.

IU would later try to have Riko Mine kill Aria H. Kanzaki, Jeanne d'Arc to turn Shirayuki Hotogi to their side, and Kyouchikytou to go after Akari Mamiya and her family. However, each of those operations resulted in failure. Then after Vlad, the #2 of IU, was defeated from the combined efforts of Kinji Tohyama, Aria H. Kanzaki, and Riko Mine, Kinichi Tohyama (Kana) enacted his plan to try and kill Aria and Patra kidnapped Aria from resulting in a battle with Kinji and Shirayuki. This caused Sherlock Holmes to reveal himself and try to convert Aria into a member of the organization until she was defeated by Kinji. Finally, IU was destroyed following the defeat of Sherlock at the hands of Kinji. However, the following power vacuum lead to the Cao Cao sisters trying to kidnap Kinji and Aria and kill Reki. This lead to the start of Far Eastern Warefare (FEW) among the organizations connected to IU and caused N to come out of shadows to replace the power vacuum.

Trivia

 * The organization is similar to the SPECTRE organization from the James Bond movies.