A quiet, unassuming painting restorer who resides at La Madrileña. Characterized as a lonely and awkward figure, he takes various medications and seems overwhelmed by his surroundings. His passive demeanor and isolated life are abruptly disrupted when he begins receiving scented love letters on pink paper from a mysterious woman.

The enigmatic woman romantically linked to Camilo. She is first introduced to the residents of La Madrileña through a series of perfumed, pink love letters arriving for the painter. Described by Camilo as the beautiful daughter of a wealthy client who lives under strict supervision, her correspondence deeply intrigues the boarding house and changes their perception of Camilo.

The widowed owner of La Madrileña boarding house. She considers herself a maternal figure to her tenants, especially Camilo, though her care often manifests as controlling and invasive behavior. She actively participates in the household's culture of social surveillance, eagerly reading Camilo's private letters while maintaining a façade of moral superiority.

A law student and resident of La Madrileña who views himself as an intellectual authority. He utilizes his academic background and obscure cultural references to assert superiority over the other boarders. He intensely scrutinizes Camilo, harboring deep suspicions about the unassuming painter's true nature and his relationship with the mysterious letter writer.

A retired schoolteacher residing at La Madrileña. She is highly observant and unabashedly intrusive, regularly eavesdropping and examining the mail to gather intelligence on her fellow tenants. She acts as a catalyst for the household's gossip, actively encouraging Mrs. Milagros to open Camilo's misaddressed letter.

The eldest daughter of Mrs. Milagros. She is highly skeptical of Camilo's romantic affairs, openly expressing disdain and speculating that his secret lover must be old or unattractive. She actively participates in reading Camilo's letters and mocking his gentle, awkward demeanor.

One of Mrs. Milagros's three daughters. Like her sisters, she views Camilo as a harmless figure and is utterly baffled by the arrival of his perfumed love letters. She actively engages in the household's obsession with his private life and romance.

A daughter of Mrs. Milagros who joins the rest of the family in surveilling Camilo. She underestimates his capacity for romance and is eager to uncover the truth behind his correspondence, participating in the collective invasion of his privacy.

The housemaid at La Madrileña. Despite Mrs. Milagros treating her dismissively and speaking of her with ableist terms, she is a silent but constant presence in the house. She carefully observes the drama surrounding Camilo and his letters without drawing attention to herself.

The late father of Camilo who passed away shortly before his son arrived at La Madrileña. He introduced Camilo to the painting profession.

The unnamed local police official tasked with investigating the central mystery of the novel. He listens patiently to the highly biased and often contradictory accounts of the various boarding house residents, occasionally asking pointed questions to cut through their personal prejudices.