Daisy is a 20-year-old medical student living in London with her older brother, Julian. She frequently feels suffocated by Julian's obsessive control over her life and her family's deep involvement in the criminal underworld. Desperate for normalcy, she finds comfort in domestic tasks like doing laundry and hopes to learn how to drive to gain independence. Her search for autonomy leads her into complicated romantic situations with men connected to her brother's organization.

Christian is an attractive, active member of the London crime scene closely tied to the Haites family. He spends significant time with Daisy, enjoying their casual arrangement and taking her out for morning breakfasts. However, his lingering attachment to his ex-girlfriend, Magnolia, prevents him from fully acknowledging his growing feelings for Daisy. He constantly wears a heart-shaped necklace that ties him to his past.

Julian is a powerful London crime lord who took control of the family business after his parents were murdered 16 years ago. Ten years older than Daisy, he acts as her parental figure and primary guardian. He loves his sister deeply but exhibits extreme, obsessive control over her social life, romantic partners, and daily movements. He regularly commands the Lost Boys gang in various high-stakes criminal enterprises.

Romeo is Daisy's childhood best friend and former boyfriend who recently returned from New York. Four years ago, he cheated on Daisy, leading Julian to exile him from their immediate circle. Despite his past infidelity, he has a long history of protecting Daisy from physical harm and understands her deeply. He actively seeks to rekindle his relationship with her, putting him in direct competition with Christian.

Magnolia is a London socialite closely tied to the city's criminal elite. She maintains a chaotic, on-again-off-again relationship with BJ Ballentine that frequently disrupts their social group. She frequently interacts with Christian, fully aware of his lingering feelings for her, and uses this dynamic to command attention.

BJ is a prominent member of the London crime circle and a core member of Julian's social group. He is famously involved in a tumultuous romantic relationship with Magnolia Parks, which frequently causes friction among his friends, especially Christian.

Jonah is Christian's brother and Julian's best friend. He is a steadfast presence in the London crime scene, regularly attending social gatherings, club nights, and meetings with the other men in the organization.

Declan is a member of the Lost Boys gang. He is loyal to Julian but has a history of stepping out of line, particularly regarding his brief, secret romantic involvement with Daisy.

Miguel is Daisy's assigned bodyguard. Employed by Julian, he escorts Daisy to school, clubs, and social events, ensuring her safety in a highly dangerous world. His constant presence represents both protection and imprisonment for Daisy.

Killian is a detective for the National Crime Agency actively investigating Julian's criminal enterprises. He regularly crosses paths with Daisy, using flirtation to gather information and cause frustration for the protective men in her life.

Eamon is a dubious client with a background in trafficking who hires Julian and the Lost Boys to steal a famous Gustav Klimt painting. His involvement introduces significant risk to the gang's operations.

Henry is a member of Christian and BJ's close social circle. He frequently hangs out at the club and observes the romantic drama unfolding among his friends, often offering commentary or trying to defuse tension.