Guts (? Gattsu?), is a wandering warrior, and former Raid Leader of the renowned mercenary unit known as the “Band of the Hawk” (? Taka no Dan?), who hunts demon like creatures called Apostles, humans who have made a deal with a group of archdemons known as “The God Hand” that in exchange for their wish they must sacrifice someone or something close to them.
After his troubled childhood under his adopted father, Guts is recruited to the Hawks by their charismatic leader Griffith. Griffith, Guts and their mercenary group play a pivotal role in ending the long war that has ravaged the country of Midland. Griffith however, in his ambition to become a ruler, seduces the King’s daughter, leading to him being imprisoned and horribly tortured until being rescued by his comrades. With his body horribly mutilated, Griffith sacrifices his friends and mercenary group to the God Hand to continue his dream in a demonic ritual, as the newest member of the God Hand himself, from which only Guts and his lover Casca, survived.
After being separated from Casca, who lost her memories due to the trauma of the ritual, Guts starts hunting down the Apostles in search for revenge against Griffith, reuniting with Casca just in time to rescue her from being burned as a witch. While Guts and Casca travel to the Elf country of Elfhelm in search for a safe haven, accompanied a group of companions they befriended during their travels, a revived Griffith reforms the Band of Hawk and leads the fight against invading forces from the east, eventually establishing his rule over Midland and founding a new, massive capital, Falconia, where the humans take refuge from the ever increasing attacks of demons, unaware that their leader is actually one of them.