Guts is a lone mercenary warrior who wanders looking for battles, driven solely by his will to survive. After being defeated by Griffith, the ambitious and charismatic leader of a mercenary group called the Band of the Hawk, Guts becomes a full member of the group. Guts quickly rises through the ranks, becoming Griffith's best warrior. One day, Griffith shows Guts his Behelit, a mysterious demonic relic, revealing him as well his dream to rule a kingdom of his own. Three years later, the Band of the Hawk have grown in power and numbers, with Guts serving as a commander of the group. Guts encounters Immortal Zodd, a fearsome giant warrior, who after nearly killing him and Griffith, spares their lives upon seeing Griffith's Behelit, warning Guts of an inescapable death should Griffith's dream die. While recovering, Griffith starts getting closer to the king of Midland's daughter, Charlotte. At one point, Guts overhears a talk between Griffith and Charlotte, where Griffith says that he only considers a true friend someone who has their own dream. The Band of the Hawk is eventually hired by the kingdom of Midland, helping to win the Hundred Year War against the Tudor empire. In the meantime, Guts develops a closest relationship with Casca, the Hawks' unit commander and only female member. Some time later after the Hawks' victory, Guts decides to leave the group to stop living for Griffith's dream. Guts and Griffith have a duel; after an overwhelming defeat for the latter, Guts reaffirms his decision and walks away. Psychologically devastated by Guts' departure, Griffith, in a lapse of judgement, has sexual intercourse with Princess Charlotte. Griffith is imprisoned and tortured, while the Hawks are marked for death.
Guts, who spent a year training to become a better swordsman, eventually learns that the Hawks are now outlaws and that Casca has taken the leadership. Guts goes to their aid, arriving in time as they battle a group of mercenaries. Casca has a plan to rescue Griffith from the Tower of Rebirth, where he is being held. Later on, they go into a dungeon under the Tower of Rebirth, finding Griffith mutilated, disfigured and rendered mute. Back from the escape, the Hawks feel helpless due to Griffith's condition. Casca tells Guts that she must take care of Griffith and that Guts should continue his own path. Overhearing them and desperate at what he has been reduced to, Griffith takes off in a wagon, accidentally crashing into the river. In his desolation, following a failed attempt to commit suicide by stabbing his throat into a sharp tree root, Griffith finds his Behelit, lost during his time imprisoned, and unintentionally activates it with the blood leaking from his neck, thus initiating an event called "the Eclipse", taking everyone present to another plane. The God Hand, a group of archdemons, inform Griffith that he has been chosen as their final member and he must offer his comrades as sacrifices to the "apostles", humans like Zodd who became powerful demons by sacrificing their loved ones and their own humanity. The entire Band of the Hawk are branded as sacrificial offerings; almost all of the group, except Guts and Casca, are slaughtered by the apostles. Griffith, reborn as the fifth God Hand member, Femto, rapes Casca in front of Guts. Guts, restrained by the apostles, cuts off his own left forearm and loses his right eye, in a vain attempt to stop his former friend. Guts ultimately survives the Eclipse and time later he becomes known as the Black Swordsman, starting a quest for revenge against the God Hand and the apostles.
Berserk was produced by Nippon Television and VAP, animated by Oriental Light and Magic, and directed by Naohito Takahashi. The series begins with the original manga's Black Swordsman arc, continuing through the Golden Age arc, covering twelve volumes (and part of the thirteenth volume) of the manga. Its twenty-five episodes were broadcast in Japan on Nippon TV from October 8, 1997, to April 1, 1998. VAP collected the episodes on VHS, with thirteen sets released from February 1, 1998, to January 21, 1999. The series was later released on seven DVDs, from April 23 to October 22, 2003. VAP released the series on a Blu-ray box set on January 18, 2012.
In North America, it was originally reported that Urban Vision was negotiating the license to series for English release. However, it was then confirmed that Berserk was licensed by Media Blasters. The English dub was produced by NYAV Post. Media Blasters released the series on VHS and six DVDs, under its Anime Works label, from May 28, 2002, to May 27, 2003. A complete DVD collection was released on November 16, 2004, and a remastered edition was released on March 10, 2009. In December 2012, Media Blasters announced that the rights to the series had expired.
In the United Kingdom, Berserk was licensed by MVM Films. The six DVDs were released from September 3, 2007, to July 7, 2008. MVM re-released the series' complete DVD collection on October 11, 2010, and the Blu-ray collection on February 6, 2017. In Australia and New Zealand, Madman Entertainment released the six DVDs between December 2, 2002 and June 18, 2003. The complete DVD collection was released on March 17, 2004, and the Blu-ray collection on February 21, 2018.