Sachiko Hidari stars as the widow of Togashi (Tetsuro Tamba), a soldier executed at the end of World War II for desertion. She cannot accept the fact that her husband was a deserter, and 26 years after the war she is still looking for the reason behind her husband's execution, and looking to restore honor to his name so he may rest in peace. She tracks down four witnesses to her his death, but their stories all conflict, resulting in a mystery akin to Akira Kurosawa's classic Rashomon. Each story she hears reveals the horrors of the war but does nothing to bring comfort or closure to what happened to her husband.
At an early age, Fukasaku saw firsthand the brutality of war and developed a cynical distrust for authority and adults-an attitude that carried through to all of his films. Fukasaku uses this film as an expression of the dehumanizing effect war has, and the horrific futility of combat.
Under the Flag of the Rising Sun is not only Fukasaku's best work; it is one of the most compelling anti-war films ever made. Other films have done wonderful jobs of showing the horrors and futility of war, and films like Coming Home, Born on the Fourth of July and Jean-Pierre Jeunet's A Very Long Engagement (which borrows heavily from this film) are excellent examinations of post-war life. But few films capture as much as this one.
Much of what fuels Under the Flag of the Rising Sun is the sustained passion Hidari has for her husband. In that regard, the film, much like A Very Long Engagement, is a love story. Fukasaku uses Hidari's undying love as a foundation to give the film a sense of humanity, which in turn elevates it above the standard war film.

