During the Hundred Years' War, the world was turned upside down, people's hearts were corrupted, and greed was rampant. Countries annexed and attacked each other, and rivers of blood flowed. A man named Guts (voiced by Iwanaga Hiroaki) made a name for himself among the mercenaries with his own strength, and also attracted the attention of another powerful man. Soon, he encountered the terrifying mercenary unit "Eagle Group" and its charismatic and powerful leader and ruler Griffith (voiced by Sakurai Takahiro). Guts was defeated in the battle to challenge Griffith, and then joined the Eagle Group and became the most brave warrior among them. In the fierce battles, he established an indestructible friendship with his comrades, and was appreciated by Griffith, who even risked his own safety to save Guts who was tortured by the demon Zod. But as the Eagles became the regular army of the Midland Kingdom and Griffith was made a noble, the simple comradeship began to be overshadowed by conspiracy... This film is based on the original work of the same name by cartoonist Kentaro Miura. It is the first part of the "Golden Age" trilogy, the other two being "Doldore Raiders" and "Advent".