Shinjuku

Shinjuku is the second capital of the Japanese Imperial Demon Army, and it is en route from vampire territory to Shibuya. It is famous for experimenting on vampires.

Details
This is a large city maintained by the JIDA. It is surrounded by high defensive walls endowed with magical barriers to repel Horsemen. Although it is well-kept since the Apocalypse, it suffers extensive damage during a vampire attack. The underground houses the experimentation for their numerous vampire guinea pigs. Sometimes, Kureto Hīragi takes the captured vampires above ground for further testing just outside the city walls.

A great deal of damage occurs at Shinjuku's 5th Street Intersection where the main forces of Guren Ichinose's Moon Demon Company and Ferid Bathory's vampire forces clash. This is also where Yūichirō Hyakuya and Mikaela Hyakuya meet for the first time in four years. When Yūichirō transforms, he destroys a few city blocks and leaves a massive crater in the ground.

Guren Ichinose can occasionally be found working in their high-tech laboratories deep within the underground Shinjuku Barracks. It also has a hospital. In chapter 14, Yūichirō rests here after the battle.

It has a Spellcraft Research Library full of information on magic and vampires. After Yūichirō Hyakuya learns that Mikaela Hyakuya has been turned into a vampire, he goes there to study up on them while he is stationed in Shinjuku. One of their books is titled A Study of the Horrors of Bloodsucking Creatures.

The Shinjuku Central Army Headquarters First Office is here as well. Inside, Kureto interrogates Shinya Hīragi, Mitsuba Sangū, Yoichi Saotome, Shihō Kimizuki, and Yūichirō Hyakuya about a traitor. He also tortures Yoichi and Kimizuki in order to make Yūichirō divulge information to him. He then tells Yūichirō about the Hyakuya Sect. The ruined city outside the walls has numerous broken buildings and damaged roads. Horsemen may appear nearby. Shinoa Hīragi takes her squad out here and away from the city in order to advance Yūichirō and Kimizuki on the next step of their Cursed Gear training.

Society
Like Shibuya, this city is ruled by the JIDA and Hīragi family, although this is not their main headquarters. They do extensive experimentation on vampires and do not consider them human. The experimentation is an open secret.

Shinjuku Arc
Vampires attack Shinjuku. The battle is close and exhaustive, but the main army of the JIDA arrives and chases off the vampire invaders. Many soldiers are stationed here afterward. The city acquires extensive damage. After the battle, Guren Ichinose goes deep underground in one of the research facilities. Shinoa Hiragi finds him there and asks him some questions. After that, Yūichirō Hyakuya continues recovering in the hospital above ground. The next week, all of Shinoa Squad aside from Shinoa are interrogated by Kureto Hiragi. He tortures Yoichi Saotome and Shiho Kimizuki in order to get Yūichirō Hyakuya to speak. He then reveals information about the Hyakuya Sect.

Later on, Kureto exposes vampires to sunlight and starvation above ground to try and force them into transforming into demons. The experiment fails, and he has them killed. Kureto then gives Guren Ichinose orders to attack Nagoya.

Trivia

 * A real place in Japan.