Maia is a literary translator in her early thirties who speaks fluent French, Portuguese, and Russian. She is the eldest of six adopted sisters and the only one who still lives at their childhood home, a secluded estate called Atlantis on Lake Geneva in Switzerland. Deeply fearful of emotional pain following a traumatic college relationship, she hides her natural beauty and lives a quiet, isolated life. Pa Salt's death forces her out of her comfort zone when he leaves her a set of coordinates pointing to Rio de Janeiro.

Bel is an 18-year-old woman living in 1927 Rio de Janeiro. As the daughter of an Italian immigrant who made a fortune in coffee, she feels stifled by her father's desperate ambition to marry her into high society. She possesses a passionate, artistic spirit that heavily clashes with the strict expectations placed upon upper-class women. She seizes an opportunity to travel to Paris before her impending marriage.

Floriano is a Brazilian novelist and historian living in Rio de Janeiro. He acts as a confident, energetic guide for Maia as she investigates her mysterious origins. A single father, he balances his creative work with raising his young daughter and providing historical tours of the city. He challenges Maia to face her fears and stop hiding from the world.

Laurent is a talented young French sculptor working as an assistant on the Christ the Redeemer statue in the late 1920s. He creates art in the modern art deco style, reflecting his bold and free-spirited personality. He frequently challenges conservative norms and quickly becomes captivated by Bel, asking to sculpt her portrait.

Gustavo is a member of an old aristocratic Portuguese family in Rio de Janeiro whose fortune is dwindling. He is a decade older than Bel, physically slight, and heavily reliant on alcohol to manage his insecurities. He pursues Bel partly to secure her family's wealth and partly out of genuine, if clumsy, affection.

Pa Salt is the deeply secretive, wealthy adoptive father of the six D’Aplièse sisters. He spent his life traveling the globe and raising his daughters at a secluded estate called Atlantis. Even in death, he exerts total control over his family by arranging a private burial at sea before his daughters can gather.

Luiza is Gustavo's haughty, patronizing mother. She fiercely protects her family's aristocratic status and treats Bel with coldness and impatience. She constantly demands strict obedience to social conventions and exerts heavy influence over her son.

Ally is the second eldest of the adopted sisters. She is a highly competitive, confident sailor with a natural charm and an outgoing personality. She shares a close bond with her sisters and feels guilty for being at sea when their father died.

Star is the quiet, shy third sister of the family. She relies heavily on her younger sister CeCe to speak for her and manage their shared life. She rarely steps out of her sister's shadow and appears physically delicate.

CeCe is an assertive, domineering artist preparing to attend the Royal College of Art in London. She acts as the protector and spokesperson for Star, maintaining an unusually tight bond with her older sister. Her forceful personality sometimes causes tension among the siblings.

Tiggy works in wildlife rescue in Scotland and possesses a deeply spiritual, empathetic perspective on life. She is the sister Maia feels closest to, having been cared for by Maia through various childhood illnesses. She offers comfort by expressing her belief that spirits simply move on to another plane.

Electra is the youngest of the six sisters, a strikingly tall fashion model living in Hollywood. She possesses a tempestuous, dramatic personality and strictly controls her diet. She is the most outwardly emotional about Pa Salt's unconventional burial.

Known affectionately as "Ma," Marina is Pa Salt's long-term employee and the primary mother figure for the six sisters. She manages the daily operations at Atlantis and helps maintain the strict privacy and secrecy that Pa Salt demanded during his life.

Beatriz is an elderly woman living in a crumbling historic mansion in Rio de Janeiro. When approached by Maia, she acts hostile toward inquiries about the past and adamantly refuses to discuss her family history or the home's previous occupants.

Yara is Beatriz's protective maid, born in the grand house a few years before her employer. She possesses a cache of historical letters that she eventually shares with Maia upon recognizing a family heirloom, providing a crucial link to the past.

Loen is Bel's maid and closest confidante in 1927. Having grown up alongside Bel, she provides practical support and a listening ear for Bel's romantic frustrations. She serves as a vital communication channel when Bel needs to exchange secret messages.

Bel's father is the son of an Italian immigrant who built massive wealth in the Brazilian coffee industry. He eagerly pushes his daughter toward an aristocratic marriage to secure their family's social standing in Rio, viewing her beauty as a tool for upward mobility.

Bel's mother acts as a traditional, compliant wife who prioritizes her family's social standing. She tries to offer Bel practical, if old-fashioned, advice about marriage and physical intimacy, encouraging her daughter to simply accept the duties expected of her.

Maria Elisa is Bel's practical, sensible friend whose father is engineering the Christ the Redeemer statue. She lacks Bel's rebellious streak and encourages her friend to accept a stable, aristocratic life, though she herself dreams of training as a nurse.

Heitor is the chief engineer responsible for constructing the Christ the Redeemer statue. He travels to Europe to find a sculptor for the statue's head and hands, acting as a strict but kindly chaperone for Bel during her time in Paris.

Paul is a renowned, energetic art professor and sculptor in Paris. He creates the head and hands for the great statue and runs the busy Parisian studio where Bel spends much of her time observing the artists at work.

Margarida is an independent Brazilian art student who introduces Bel to the bohemian lifestyle of Montparnasse. She teaches Bel how to skirt their chaperones' rules to enjoy Parisian cafes and freely interact with male artists.

Zed is Maia's former college boyfriend. His unexpected attempt to contact her fourteen years after their painful breakup drives Maia to impulsively flee Switzerland for Brazil just to avoid running into him.

Kreeg is Zed's father and the owner of the boat Olympus. Suffering from terminal cancer, he dies by suicide at sea, an event that deeply unsettles Maia due to the timing of her own father's marine burial.

Georg is Pa Salt's reserved, thoughtful lawyer based in Geneva. He executes his client's unconventional will, handing out mysterious letters and coordinates to the sisters while managing the family's financial trust.

Gustavo's father is an aging Portuguese aristocrat struggling with his family's dwindling finances. He displays more empathy and tact than his wife, offering business support to Bel's father when the stock market crashes.

Valentina is Floriano's precocious six-year-old daughter. She shares a close, loving bond with her single father and quickly charms Maia with her enthusiastic, if unsuccessful, attempts to cook dinner.