Lorelei is the matriarch of the Bird family, living in a picturesque Cotswolds home. She is lively and bohemian, obsessed with creating the perfect environment for her four children. She insists on elaborate Easter egg hunts and preserving every piece of their childhood art. Her enthusiastic collecting borders on a severe hoarding condition, a habit stemming from her own difficult upbringing. She uses her bright charm to deflect from underlying anxieties and struggles to let her children grow up.

Colin is Lorelei's husband and a college lecturer. He is patient to the point of being passive, preferring to keep the peace rather than confront his wife about the state of their home. Though he occasionally tries to mitigate the mess by secretly throwing things away, he generally yields to her strong personality. His conflict-avoidant nature creates distance between him and his children.

Megan is the oldest of the Bird children. Pragmatic and observant, she is the first to label her mother's collecting as a serious problem and pushes against the family's enabling behavior. She seeks control over her environment, striving for a neat, orderly life in London that strictly contrasts with the chaotic home she grew up in. She often clashes with her relatives over their refusal to face reality.

Bethan is the second oldest of the Bird children. Unlike her sister, she is passive and deeply entangled in her mother's world, feeling a strong sense of duty to remain at the family home. She struggles to define herself independently and often adopts the styles and habits of those around her. She grapples with a desire for a normal life while feeling anchored to her childhood bedroom.

Rory is Rhys's twin brother. Growing up, he is the more popular and outgoing of the twins, though he is highly susceptible to peer pressure. He finds his family's home life increasingly stifling and longs to break free from the stagnation that permeates the house. He seeks an entirely different lifestyle by traveling abroad and attaching himself to new mentors.

Rhys is Rory's twin brother. He is a solitary, withdrawn boy who struggles to make friends and is placed in the unpopular class at school. He frequently retreats to his room to listen to grunge music and harbors intense, confusing emotions. His isolation deeply affects the entire family, as he relies heavily on his mother for attention.

Vicky is the Birds' vibrant next-door neighbor. With her dyed blonde hair and strong perfume, she possesses a warm energy that quickly integrates her into the Bird household. She is fiercely devoted to Lorelei, trying to manage the chaos of the house while balancing the needs of her own daughters. She often attempts to fix problems by people-pleasing.

Molly is Megan and Bill's daughter. She contrasts the chaotic Bird family history with her mother's strict, orderly upbringing. Curious about her extended family, she attempts to understand her relatives without the heavy baggage of the past. She views their unconventional lives with a pragmatic and accepting attitude.

Kayleigh is a forthright young woman with a difficult background, marked by overplucked eyebrows and a highly independent streak. As an outsider to the Bird family, she quickly identifies the unhealthy dynamics at play in their house. She encourages Rory to seek a life beyond his mother's walls, providing him with a catalyst for change.

Jim is a widower living in Northern England with his dog. He connects with Lorelei on a dating website, exchanging long emails about their lives. He provides Lorelei with a safe, non-judgmental space to discuss her past, encouraging her to take steps toward independence and self-reflection.

Bill is Megan's partner. He shares a highly structured life with her in London but occasionally chafes under her intense need for order. He appreciates a more relaxed environment, which sometimes causes friction in his domestic life.

Maddy is Vicky's older daughter. She spends significant time in the Bird household but becomes increasingly frustrated as Lorelei's clutter encroaches on her living space, eventually demanding personal boundaries.

Sophie is Vicky's younger daughter. She is accommodating and helpful, often taking on caretaking tasks when the adults in the neighborhood are overwhelmed.

Owen is a builder from Essex who lives a carefree, bohemian lifestyle abroad. He becomes a role model for Rory, who admires his independence and lack of traditional attachments.

Tia is Kayleigh's young daughter. She grows up in a Spanish commune and is eager to connect with her extended relatives in England, bringing a new generation into the complex family dynamic.