Gate 0: Jieitai - Ginzai nite, Kaku Tatakaeri #1

Gate: Jieitai Kanochi nite, Kaku Tatakaeri, often referred to as Gate, originated as a web novel series published by Takumi Yanai on the user-generated site Arcadia before being adapted into a light novel series illustrated by Daisuke Izuka. The narrative explores the geopolitical and military tensions that arise after a mysterious portal opens in modern-day Ginza, Tokyo, allowing an imperial army from a fantasy world to invade. The franchise is known for its blend of military fiction and high fantasy tropes, focusing on the deployment of the Japan Self-Defense Forces to bridge the two disparate realities.

The specific iteration noted as Gate 0 serves as a supplementary or side-story expansion of the established lore. Designed to deepen the world-building of the original series, these works maintain the franchise's signature aesthetic which contrasts advanced modern weaponry with traditional fantasy designs. While the series has garnered a dedicated following for its unique premise and tactical detail, it has also been a subject of critical discussion regarding its political themes and portrayal of nationalist sentiment within the Japanese fantasy genre.