Rob is a 35-year-old man who owns Championship Vinyl, a struggling record store in London. He is highly cynical, insecure, and obsessed with pop music, frequently organizing his life and preferences into arbitrary "top five" lists. Following his recent breakup, he decides to track down his most memorable ex-girlfriends to understand his chronic romantic failures.

Laura is a pragmatic lawyer who recently ended her relationship with Rob. She previously worked for a legal aid group but recently transitioned to a higher-paying, more corporate firm due to market changes. Frustrated by Rob's lack of ambition and constant negativity, she seeks a new path forward in her life, moving in with their former neighbor.

Ian is the former upstairs neighbor of Rob and Laura. He provides Laura with a place to stay after she moves out. Rob views Ian as a pretentious and annoying individual with terrible taste in music, projecting his own deep insecurities onto the man who replaced him.

Barry is a loud, brash, and obnoxious part-time employee at Championship Vinyl. He frequently bullies customers who try to purchase records he considers inauthentic or tacky. An aspiring musician, he continually places advertisements in the store seeking bandmates to start his own music group.

Dick is a 31-year-old part-time employee at Championship Vinyl. Shy, socially awkward, and conflict-averse, he possesses an encyclopedic knowledge of music. He patiently guides customers toward good purchases and prefers to remain a passive observer of life rather than risk failure or rejection.

Marie is an American singer-songwriter who recently relocated to London following a difficult breakup. She performs cover songs and possesses a direct, practical outlook on life and romance. She shares Rob's deep interest in music and provides a direct contrast to Laura's pragmatic, non-musical lifestyle.

Alison is Rob's first memorable heartbreak. They grew up together in suburban England in the early 1970s and dated for a matter of hours as young teenagers before she developed an interest in one of Rob's friends.

Penny was a wholesome teenager whom Rob dated shortly after Alison. He broke up with her because she felt too young to be physically intimate, an event that caused her significant emotional distress and distorted her early views on relationships.

Jackie originally dated Rob's friend Phil for years. Rob seduced her out of envy for their happiness, but their brief time together was miserable. She eventually broke up with Rob and returned to her original partner.

Charlie is the woman whose departure caused Rob the most psychological damage. Glamorous, dramatic, and exotic, she dated Rob in college before leaving him for another man. Her rejection caused Rob to flunk out of school and permanently retreat into his music obsession.

Sarah is the woman Rob dated after Charlie. Still wounded, he viewed her as a suitably average match who shared his moderate intelligence and recent heartbreak. They moved in together until she unexpectedly met someone else and left him.

Lisa is a close friend of Laura who finds herself acting as a reluctant intermediary following the breakup. She disapproves of Rob's toxic behavior but also holds a low opinion of Laura's new partner, Ian, placing her in a complicated middle ground.

T-Bone is an American musician who performs as a duet partner with Marie LaSalle. He frequently spends time drinking with the staff of Championship Vinyl after concerts.

Anna is Dick's new girlfriend. She matches his quiet, awkward demeanor perfectly and enjoys mainstream music that Dick's coworkers normally consider embarrassing.

Phil is a former friend of Rob. He was in a happy, long-term relationship with Jackie Allen, which Rob briefly interrupted out of sheer jealousy before Phil and Jackie reunited.

Kevin is a former schoolmate of Rob in suburban England. He is the boy for whom Alison Ashworth left Rob when they were teenagers.

Paul is a lawyer who works with Laura at her new corporate firm. Rob initially imagines him as a threatening, cultured rival, but discovers he is actually a kind, grounded individual with a sparse record collection.

Miranda is Paul's partner. She and Paul host warm, inviting dinner parties and share a relatively simple record collection that Rob struggles not to judge.

Caroline is a music journalist for a local newspaper. She interviews Rob about his upcoming DJ appearance and shares his highly specific tastes in pop culture, presenting a temptation to his personal growth.

Clara is a friend of Charlie Nicholson. Charlie invites her to a dinner party with the specific intention of setting her up with Rob, hoping to demonstrate the type of woman she feels Rob actually deserves.

Jo is Laura Lydon's sister. She supports her family during difficult personal times and provides insight into Laura's emotional state during a period of grief.