- "The battle that marks the downfall of the Empire" — The depiction of the battle.
The Battle of Ginza, also known as "The Ginza Incident"(銀座の戦い また知っている 銀座事件は、Ginza no Tatakai Mata shitte iru Ginza jiken wa,) was a battle which occurred in the Ginza shopping district where the population of Japan faced off against the Imperial Army, who invaded through a Gate from another world.
Initial Imperial Incursion
In summer 20xx, a portal to another world appeared in Ginza, from which stormed a Roman-like army which included infantry and cavalry, as well as "fantasy" creatures such as dragons and goblins. The invading army begin to indiscriminately attack civilians, causing a few hundred deaths and taking an unknown number of civilians back through the Gate as slaves. The Imperial Army, believing they had conquered the new world, arrogantly proclaimed the city as theirs, though they had no idea that there were more lands, along with the fact that they had just provoked an enemy far stronger than them and that they only captured a small city.
Though the police had submachine guns and pistols, the sheer numbers of the Imperial Army overwhelmed the few police officers on duty. The JSDF were immediately called in to stabilize the situation, but it would take some time before they arrived.
Siege of the Japanese Imperial Palace
Yōji Itami, an off-duty JSDF lieutenant attending a doujinshi sale in Ginza intervened, taking command of the police force and evacuating civilians to the Japanese Imperial Palace, as well as personally killing one Imperial soldier in hand-to-hand combat. Itami and the police guarded the palace gates, arming themselves with tactical police equipment and maintaining the defence of the Imperial Palace.
The Empire attempted to breach the palace walls with ladders, trebuchets and through the gate, but these attempts were easily repelled by the police force, who were more concentrated and used their firearms to easily kill all incoming attackers.
Sometime after the palace was being held by the police force, the JSDF arrived, an Asagiri-class destroyer began shelling hostile positions while Cobra assault helicopters began mopping the skies of hostile dragon riders before proceeding to sweep the ground of hostile enemy forces. The Empire was unprepared for the sheer firepower of their adversaries, and began a hectic retreat back to the Gate. At this time, the police force defending the Imperial Palace began pushing the Empire back to the Gate, and captured those who did not flee in time or were killed by the barrage. Roughly 60,000 men from the Empire were killed during the rout.
For his intervention, Itami was promoted to First Lieutenant, and later, the JSDF set up base and sent a Special Task Force into the Special Region to explore the new territory, eliminate any possible threats, and set up peace negotiations with the people on the other side of the Gate.
Since the Japanese had taken many prisoners during the battle and had no idea what to do with them, they simply sent them to a prison island where they were integrated with the demi-human auxiliaries. The Imperial officers and nobles had great difficulty adjusting to their new prison life, as they felt entitled as high-ranking military officers and nobles and that they should be treated as such, but were enraged when they had to share their space with lower-ranked humans or even the demi-humans. With slow peace talks between Japan's government and Piña Co Lada, most of the human prisoners would be eventually returned to the Empire.
It was also revealed that most demi-humans were brought to the US to be dissected for study after the US negotiated with the Japanese.