Devil May Cry Volume 1 is a novel written by Shin-Ya Goikeda with the assistance of Hideki Kamiya, the series creator. It spans from the death of Dante's mother Eva until the beginning of the first Devil May Cry, although as of release of Devil May Cry 3 it is considered non-canon. Hideki Kamiya was able to work closely with Goikeda during the development of the novel, stating that his depiction of Dante and Goikeda's depiction are very similar.
There is a Second novel, which is taking place after Devil May Cry and before Devil May Cry 2, was also released. Unlike the first novel, it is possible the second novel could be canon as it can sit easily between DMC4 and DMC2.
The novel begins with Dante, under the alias Tony Redgrave, confronted by the thug "Mad Dog" Denvers for the ninety-ninth time. Dante kills all of Denvers' men and leaves. As Denvers reminisces about how Dante's appearance two years previously caused the fall of the local underworld, he is killed by scythe-wielding devils screaming Dante's name.
In Bobby's Cellar, a mercenary hideout, Dante talks with his partner Grue. He then leaves Bobby's Cellar, heading to Goldstein's Shop, run by gunsmith Nell Goldstein. Bantering with Nell, Dante mentions he wrecks guns quickly due to the rate of fire he employs. Returning to Bobby's Cellar, Dante acquires a lucrative job with Grue. During the job it becomes clear to Dante and Grue that it is too dangerous, so they retreat. Later, as both men evaluate the aftermath of the pitched battle, they are attacked by the corpses. Dante destroys them, though Grue freezes. Afterwards, Grue and Dante eat dinner with Grue's family.
At Bobby's Cellar Enzo introduces a new mercenary named Gilver, a tall man swathed in bandages who wields a katana. Gilver fights Dante, proving himself equal. Deciding to settle the fight with drinking, Dante wins and Gilver is robbed by the bar patrons. After leaving, Dante is beset by demons and the undead Denvers. Dante awakens in the home of a local woman, who he spurns before leaving. He learns that killing Denvers has led to a bounty being placed on his head by the Oz Club. He leaves to confront the club directly. Entering a bank, he fights the same demons once again. Defeating them he runs into Gilver, who has slaughtered the Oz Club.
Weeks later, Dante and Gilver are now being paired on numerous jobs and Grue is missing. On the way to work, Dante stops by Nell's home, giving him two handguns and warning him about Gilver. Dante runs into Grue, who has been taking assassination jobs. After leaving Dante, Grue kills a heavily in debt thug. This sparks a demonic transformation among the thug's friends and Grue's hiding place is revealed by Gilver. Grue ignites a grenade on his chest, trying to kill Gilver. Dante and Gilver continue as partners, and Enzo reveals that Grue did assassinations because of his daughter Jessica's illness. Dante goes to the hospital and finds it overrun by demons. Dante faces the demon in charge, who is feeding on Jessica's despair. He kills the demon and Jessica, shattering the connection between the human world and demon realm.
Due to the hospital massacre and Grue's disappearance, Dante is publicly scorned by other mercenaries. Gilver converts the patrons of Bobby's Cellar into demons while Dante goes to Nell Goldstein's for rest. Soon after he leaves, an explosion engulfs Goldstein's Shop in flames. Dante charges in, finding Nell working on two handguns made especially for him: Ebony and Ivory. Giving him the handguns, Nell dies. Dante ceases using the Tony Redgrave alias. Dante returns to Bobby's Cellar and confronts Gilver. Amidst a furious sword fight, Gilver shoots Dante with the shotgun purchased at Nell's shop. Fatally shooting Gilver in turn, Dante is horrified to discover that Gilver is his brother Vergil.
Much later, Enzo drops by Bobby's Cellar and helps Dante leave. In the novel's epilogue, Dante sits in his shop as Devil May Cry begins.
After the release of Devil May Cry 3, contradictions between the game and this novel forced much of the story of the novel out of canon. Of particular concern is the Gilver/Vergil's fate. Because of the events of Devil May Cry 3, the community generally accepts that Vergil cannot be Gilver, and thus, the sequences of the novel involving him are non-canon.
However, parts of the novels might still remain within the canon story. Dante's alias as "Tony Redgrave" is also mentioned in the Devil May Cry: The Animated Series and engraved on the on all appearances of Luce and Ombra and Ebony and Ivory. Also, the novel provides the only explanation as to where engraving ".45 Art Warks" comes from.
Another note is that Devil May Cry 3 makes reference to Dante and Vergil fighting multiple times before the events of the game. As Dante and Vergil are twins with similar powers, Vergil's body was left on the ground full of bullet wounds at the end of the novel. As Dante has taken several injuries himself in the novel and through the series, Vergil could have recovered and became the same one faced as a character in both the Devil May Cry 3 manga and Devil May Cry 3 game.
If the novel were to become canon, the biggest controversy, the novel's epilogue, would need to removed entirely and the novel would be placed before the Devil May Cry 3 manga in the canon.