"Seven Days War" is an anime film adaptation of Osamu Soda's novel, set in the late 1980s. The story centers on a group of high school students who, disillusioned with societal expectations and adult authority, decide to stage a rebellion by occupying an abandoned underground military facility. The group, led by Mamoru Matsuno, includes his childhood friend Nanami Kiuchi, the rebellious Aya Ijūin, the quiet and observant Takashi Nomura, the resourceful Jun Tsuburaya, and the pragmatic Keisuke Tsukimoto. Each character brings their own motivations and struggles, reflecting the broader themes of youth alienation and the desire for freedom.

The narrative begins with Mamoru and his friends planning to escape their mundane lives by creating a temporary utopia away from societal pressures. They choose an old military bunker hidden beneath a rural town as their hideout, symbolizing their rejection of the adult world's control. As the group settles into their new environment, tensions arise from both internal conflicts and external threats. The students must navigate their relationships, confront their fears, and grapple with the consequences of their actions.

The plot intensifies when the group discovers a young runaway, Anna, hiding in the bunker. Her presence complicates their plans, as her mysterious background and connection to a powerful political figure draw unwanted attention. The students' rebellion becomes a high-stakes game of survival, forcing them to confront not only the authorities but also their own moral dilemmas. The story explores themes of friendship, loyalty, and the clash between idealism and reality, as the characters are pushed to their limits.

Throughout the seven days of their occupation, the group faces escalating challenges, including resource shortages, internal power struggles, and the looming threat of discovery. The film balances moments of camaraderie and humor with darker, more introspective scenes, highlighting the complexities of adolescence and the search for identity. The climax sees the students making difficult choices that test their resolve and reshape their understanding of freedom and responsibility.

"Seven Days War" is a character-driven narrative that captures the spirit of youthful rebellion while examining the consequences of defying societal norms. The story's setting and time period add a layer of historical context, emphasizing the universal struggles of growing up and the desire to carve out a space for oneself in an often oppressive world. The film's exploration of its characters' emotional journeys and the moral ambiguities of their actions makes it a compelling portrayal of adolescence and resistance.