There is a point in The Story of the Lost Child, the final part of Elena Ferrante’s acclaimed Neapolitan quartet, when the narrator, Lenù, feels ground down by her surroundings. “I had the impression, in my moments of greatest unhappiness, that the chaos of Naples had settled even in my body.”

In another Naples-set novel by another Naples-born writer, the two main characters find themselves equally infused by the city’s chaos but also charged by its vibrancy. Erri De Luca’s The Day Before Happiness sounds like a chronicle of 24 hours of misery. In actual fact it is a relatively sunny coming-of-age tale in which a young orphan boy recounts his childhood and his relationship with his adult guardian. However, shadows from Naples’ wartime past haunt one character and a vengeful camorrista threatens the other, and as a safe stamping-ground turns into a hostile battleground, both find themselves forced to redefine their place in the city.

De Luca’s nameless narrator lives alone in a little room in an apartment. He explores the walled-up trapdoors and hidden passageways of abandoned flats, and plays football in the courtyard with older boys who give him the nickname “monkey” for his ability to climb onto roofs and balconies. Not that he is a feral tearaway. He enjoys school, enthusiastically learns Latin (“a language devised by some puzzle-setter”) and devours the second-hand books lent to him by bibliophile bookseller Don Raimondo.

But it is another Don who takes him under his wing. Don Gaetano, the apartment caretaker, brings him food, teaches him to play scopa, imparts hard-won wisdom and regales him with stories about his life. Through his tales, both he and Naples come alive. We hear how he sheltered a Jew in 1943, participated in the uprising that drove out the Germans and the Fascists, and helped dig up unexploded bombs for the American liberators.

For a while, the novel is powered by a combination of charm, warmth and simplicity. Our narrator may be poor and parentless but his life comprises no hardscrabble toil or struggle, and the only darkness he encounters is in Don Gaetano’s anecdotes. But when he turns seventeen he is reunited with Anna, a girl from his past who has since become psychologically damaged, and from here the narrative acquires a queasy tension. Hopes are dashed, violence looms, secrets are spilled and happiness proves to be short-lived.

De Luca is one of Italy’s bestselling authors and, with over 60 books to his name, also one of the country’s most prolific. His novels have been translated into many languages and several have been published in America. Bizarrely, The Day Before Happiness is the first of his novels to appear in English on this side of the Atlantic. Jill Foulston’s fluid new translation convincingly renders De Luca’s smatterings of colourful Neapolitan dialect and leaves us wondering if his lovers’ sweet-nothings were just as ludicrous in the original (“Your eyes are like the curves on the keel of a boat”; “Your trembling is only a down-payment”).

At 114 pages, the novel is slim but it is by no means slight. Around his fleshed-out main characters De Luca gives deft thumbnail sketches of neighbours, including La Capa the malapropism-prone cobbler, Signorina Scafarèa with her fly-slaying halitosis, and Oreste and Pilade, twins so alike that even their parents cannot tell them apart. Don Raimondo enchants as he sings the praises of used or “banished” books (“A book’s second life is its best”) while Don Gaetano’s meditations and observations contain gem-like apercus. “The osteria is better than the theatre – every table’s a comedy,” he informs his protégé. “No tragedies – they only put on light fare.”

De Luca is adept at serving up both tragedy and comedy within the same scene. One summer Don Gaetano is teaching the narrator basic plumbing and electrical work. He sends him off to fix a widow’s bathroom sink. She seduces him: “And that was my first repair job.” Their liaisons continue until autumn when she comes out of mourning and no longer needs him. Poignancy gives way to wry humour at regular intervals throughout the book, and the result is a brittle, lyrical, finely poised tragicomedy.

At one stage Don Gaetano tells the boy that he has to teach him then let him fend for himself. “With the city, too,” the narrator replies. “It had to teach me, then let me go.” When he finally breaks free we take leave of him and his hometown, grateful to De Luca for relating so vividly and compellingly a little of their chequered histories.