Saiba Midori? - Midori is dead

Kivotos: Kivotos was made from the union of thousands of academies. The academies are divided into mostly independent districts. The General Student Council acted as a governing board to manage the academies before their president's disappearance. After that, the city became a de facto anarchist society. Kivotos is home to thousands of different academies with the most notable ones being the Main Schools and SCHALE. Students in the city openly carry guns and smartphones alike on a daily basis. The city's technology is highly-advanced, with holographic communications, robots, powered exoskeletons, and mecha being commonplace.

Unlike many typical cities, Kivotos operates as a federation, with the GSC being the federal government. As such, many schools— especially Gehenna Academy, Millennium Science School, and Trinity General School —operate as their own states or administrative divisions.

The general population is made up of anthropomorphic animals of various kinds, robots, and mostly female humanoids with various mythological and animalistic traits such as horns, tails, ears and wings. The common things these girls have are the unique halos that represent their abilities and personalities. The humanoid girls are the main focus of the story.

Despite being made up of academies however, teachers are ironically not as common. Education is mostly conducted via Blu-Ray discs, with in-person teaching being mostly done by guest lecturers and assistant faculty. Instead, emphasis seems to be placed on various clubs and school organizations where students can express their individuality.

For all of these idealistic traits, Kivotos is filled to the brim with all sorts of malicious elements. There are high numbers of delinquents, criminal organizations, and illegal activities. There is an entire district saved for the Black Market. Gun violence is also a regular occurrence.

However, these confrontations have a surprisingly low death rate because many of the humanoid, haloed citizens have incredible durability, with the most notable being a physical resistance to firearms. Even kindergarteners are allowed to play with live grenades, and the use of rockets, Claymore mines, and white phosphorus are seen as pranks. Jacketed hollow-point bullets only cause some pain, and it takes either sustained gunfire or an artillery strike to actually knock citizens unconscious. The quickest way to kill them is to destroy the halos, usually by over stressing how much protection a halo can withstand, though long term poor health, starvation, and other semi-organic natural causes could also cause death.

According to the Bond story of Sunaookami Shiroko (Riding ver.), Kivotos is implied to be approximately the size of the United States and Canada from our world combined.

Millennium Science School: Millennium Science School is an academy focusing heavily on STEM fields and associated research and development. Although established only relatively recently, it is highly regarded for its cutting-edge science and technology that is unrivaled by other schools, and it holds influence comparable to Trinity General School and Gehenna Academy. Millennium is the newest of the Three Great Academies of Kivotos, valuing logic and technical skill over all else. Because of it, they stand at the forefront of scientific research and attract many students who desire to study math or science. Although Millennium lacks the long-standing traditions and history of Trinity and Gehenna, their scientific advancements have resulted in much of Kivotos' infrastructure being produced or otherwise originating on their campus.

Every year, the school holds a large-scale contest known as the Millennium Prize, where clubs all throughout the school compete with the results of their club activities.

In the Code: BOX event, it is revealed that Millennium operates its own railway.

In the past, a group of researchers came together in an effort to solve seven difficult problems unsolvable by current technology, called the Millennium Problems. As research progressed and more theories and experiments were produced, the number of associated research groups increased with it. Eventually, Millennium as a school was formed by these research groups, and Seminar was placed at its head.

Game Development Department: In contrast to their school's motto, this club is focused on making retro games. One can mistake it with a typical gaming club.

This club is the main focus of the Millennium Arc, Clockwork Flower Pavane. During the arc, the club is in danger of being dissolved due to A.) only having three members and B.) not having made any notable accomplishments for the year.

During the act, Sensei of SCHALE was tasked (forcibly conscripted) by the Saiba twins Momoi and Midori to help them solve these problems in order to save their club. Although later involving butting heads directly against Yuuka of Seminar with aid from other departments, especially Veritas who needs The Optimus Mirror System to crack the mysterious G.BIBLE.

By the end of the first chapter of Vol. 2, with Aris' recruitment and the unexpected double whammy of the special achievement award and the incredibly positive critical reception to their game, the club was successfully saved and had its permit renewed for the rest of the year.

During the events of the second chapter of Vol. 2, the club's problems didn't end there, as sometime later, the problem comes from Alice's mysterious past and her connection to the Nameless Priests. This yet again got them at odds with Seminar, only now, they're against President Rio who considers Alice a danger to not only Millennium, but Kivotos as well. Thankfully, backed with her own friends, especially Neru, and Sensei, she fights for her safety as well as to deal with the mysterious being that possess her.

In Volume F, Where All Miracles Begin, the club, along with RABBIT Platoon and Hina, are fighting against Shiro and Kuro to take down the third false sanctum. They also participate in the conquest of Ark of Atrahasis and battle against Phrenapates as Utnaphistim's Ship's crew and combatants, bringing Sword of Light: Supernova of Atrahasis as the ship's main gun.

In Volume EX, they were called once again, this time under the command of Sensei and Rio. The club is wearing Parka suits this time around to continue their quest against Decagrammaton, alongside with Toki, Eimi and Himari. Another member is added in the club, Kei. (who is revived under a heavily modified AMAS Robot.)

This club is also the main focus of Warning of White Chalk. Mistaken for C&C by someone named Meitaro, they have to masquerade as maids to protect an art exhibit from the Phantom Thief. After dealing with the Phantom Thief, they found out about the true nature of Meitaro and the art exhibit. The club, along with the Phantom Thief and Toki that appeared in bunny suit, has to work together to deal with the guards and Meitaro, that happens to hire another group of guards.

In Code: BOX, they appeared as part of the supporting cast. During the Millennium Expo, they opened a booth, showcasing their new game. One day, the game was hacked by an unknown actor so that it induced anger from the players, causing a commotion.