Gate: Jieitai Kanochi nite, Kaku Tatakaeri Gaiden  

Gate: Supplementary Biography, ゲート 自衛隊 彼の地にて、斯く戦えり 外伝, Gate Gaiden: Jieitai Kanochi nite, Kaku Tatakaeri, ゲート外伝 自衛隊 彼の地にて、斯く戦えり

In August 20xx, a portal to a parallel universe, known as "The Gate," appeared suddenly in Ginza, Tokyo. Monsters and armies emerged from the portal, transforming the shopping district into a bloody inferno. The Japan Ground-Self Defense Force (JGSDF) immediately took action and pushed back the mythical creatures towards the "Gate." To facilitate negotiations and prepare for future battles, the JGSDF dispatched the Third Reconnaissance Team to the "Special Region" located on the opposite side of the Gate. Youji Itami, a 33-year-old JSDF officer and avid otaku, was appointed as the leader of the team. Despite facing attacks from enemy troops, the team visited various places and learned about the local culture and geography. Thanks to their humanitarian efforts, they gradually reached out to the locals, forming friendships with a cute elf, sorceress, and demigoddess. On the other hand, major powers outside the Gate, such as the United States, China, and Russia, were intensely interested in the abundant resources available in the Special Region. They began exerting diplomatic pressure on Japan, viewing the portal to the unknown world as a potential asset for toppling the international order. However, to our protagonists, it was an invaluable opportunity to broaden their knowledge, friendships, and ultimately their perspective towards the world.