Alfonso is Don Achille and Donna Maria’s son and Stefano and Pinuccia’s brother. He’s a classmate of Lila and Lenù, and when the three of them are young (when Don Achille is still alive), Lila and Lenù feel compelled to show deference and respect to Alfonso for reasons they don’t fully understand. After Don Achille’s death, however, Lenù begins developing a genuine friendship with Alfonso when the two of them head to middle school and eventually high school together. Alfonso is sweet, quiet, and smart, though throughout the latter half of the novel, he seems sad and self-conscious about living in the shadow of his older brother, Stefano.