- "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 and war prisoners. Several officers of the invading army raised the flag of their nation and arrogantly declared the annexation of the country of Japan as part of the Empire. The Imperials sustained a few casualties from the small arms and sub-machine gun carried by police officers on the scene but they eventually overwhelmed the officers due to their vast number.
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 including handguns, shotguns, submachine guns, tear gas, and riot gear. The Imperial (as in the Empire) Army laid siege to the (Japanese) Imperial Palace by attempting to climb the walls using ladders, and employed battering rams and trebuchets against the palace gates and walls, but were held off by the sustained firepower of the police firearms.
Shortly after the initial invasion, JSDF ground forces, supported by helicopters and naval fire from an Asagiri-class destroyer, counterattacked against the Imperial army, decimating the enemy forces with far superior firepower. Over 60,000 Imperial troops are estimated to have been killed, and almost as many were taken as prisoners from the police force using water cannon, tear gas and anti-riot gears.
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 other world cultures.
All surviving Imperial troops, generals and noble were imprisoned in Japan's prison island. During this time, while the Imperial troops know their place as POWs, the warden and prison guards in charge of their imprisonment stated that Imperial nobles and generals were hard to keep them in line as their arrogance, condescending and haute nature often made them clash with prison guards about their prison treatment since these people were too close-minded to understand their situation and shallowly expect their enemy to treat them like royalty and noble much like other nations in the Special Region.
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.