Sadera is the Capital of the Empire, centered around a tall hill upon which the main Imperial Palace, home to the emperor himself, stands.
Located below the hill are smaller palaces of the Imperial family, including the South Palace, home of Zorzal El Caesar, as well as the Azure Palace, which is located in an unspecified direction from the Imperial Palace, and is located near the main Temple to the gods of the Special Region. To the east of the Imperial Palace lies the mansion of Piña Co Lada. The Imperial Senate is located on one side of a large open forum, presumably a central meeting place of the city. The residential and commercial areas sprawl outwards from the palace, the most infamous of these neighborhoods being Akusho, a crime-ridden slum located on the southeastern outskirts of town.
The city's water come from multiple aqueducts. Overall, the architecture of the city has an appearance similar to that of ancient Rome, including common use of large marble structures, including columns, domes, and statues. Sadera is stated in the manga to have a population of about one million people, presumably the largest city in the Empire.
Normally, Humanoids are not welcomed into the Capital; however, after the Siege of the Jade Palace where the Humanoids of Akusho had contributed in rescuing the pro-peace faction, this social norm had deteriorated where Humanoids were allow to go to the Capital to witness Piña Co Lada's coronation as the Crown Princess.
The Imperial Palace is located at the top of Sadera Hill with at least one wide boulevard leading into it. In front of the palace is one of multiple large squares or forums seen in landscape views of the city.
The Imperial Senate is located in a prominent location in Sadera near a large forum, and is a large marble structure with a large dome. The building was the central meeting place for the Imperial Senators to enact legislation until it was bombed by JSDF aircraft as a warning to release the Japanese slaves in the Empire. Despite its destruction, the demolished building is still being used for meetings.
Multiple squares or forums exist in the city, similar to real-world ancient Roman cities. These are central public places where residents can gather and merchants can conduct business. These forums are often located near major public buildings, including the Imperial Palace, the Senate, as well as temples to the gods.
A temple is described as located along the main road leading to the Imperial Palace. This is presumably the main temple dedicated to the Special Region's gods. Given the number of residents in Sadera, it is likely there are numerous smaller temples in the city.
Located at the foot of Sadera Hill, along the main road running to the Imperial Palace from the south is the South Palace, home of Zorzal El Caesar. In addition to being Zorzal's luxurious residence, the palace also holds a darker side. Several of Zorzal's sex slaves are kept imprisoned in a room in the palace.
Akusho is an area located near the outskirts of Sadera, the furthest neighborhood from Sadera Hill. The region is a poor, violent slum controlled by gangs of criminals. In order to maintain a low profile, the JSDF also placed a small outpost here. One of the gangs of Akusho tried to attack the JSDF, but was easily beaten back by the superior firepower of the Japanese military.
A palace named for its green walls, the Jade Palace was appropriated by the Japanese for use as an embassy. According to the terms of the treaty, it is, as is the norm for embassies on Earth, technically considered part of Japan.