My Brilliant Friend by Elena Ferrante

Set primarily in a working-class neighborhood of Naples during the 1950s, My Brilliant Friend chronicles the complex friendship between Elena Greco (called Lenù) and Raffaella Cerullo (known as Lila). The novel opens in 2010 with Elena, now in her sixties, learning of Lila's disappearance. This prompts Elena to begin writing their shared history from childhood.