Briana is an emergency room doctor finalizing a difficult divorce after ten years of marriage. She acts as the primary caregiver for her brother, Benny, who suffers from renal failure. Deeply affected by her father's childhood abandonment and her husband's infidelity, she is highly protective of her emotional state and initially swears off romantic relationships.

Jacob is a new emergency room doctor at Royaume Northwestern Hospital. He has a severe anxiety disorder that makes social situations highly stressful, frequently causing others to misinterpret his behavior as rude or standoffish. He transfers to the new hospital to create distance from his recent breakup, expressing himself best through written letters and journals.

Benny is Briana's 27-year-old brother. He suffers from renal failure caused by an autoimmune disorder and requires daily dialysis. Due to a rare blood type, he faces a difficult wait on the transplant list, which severely impacts his mental health and living situation.

Amy is Jacob's highly energetic ex-girlfriend. During their relationship, she frequently organized surprise parties and outings to crowded venues, failing to understand or accommodate Jacob's severe social anxiety. She is now engaged to Jacob's younger brother, creating significant tension within the Maddox family.

Joy is Jacob, Jeremiah, Jewel, and Jane's mother. She works professionally as a couples and sex therapist. Unlike Jacob, she is highly outgoing and energetic, but she respects his boundaries and offers advice only when he asks for it.

Rosa is Briana and Benny's mother. After her husband abandoned the family while she was pregnant with Benny, she worked intensely to provide for them. She is heavily involved in her children's lives, eagerly offering cooking, cleaning, and unsolicited dating advice.

Alexis is the former head of the emergency department at Royaume and Briana's closest friend. She currently stays at Grant House, an old bed and breakfast, and provides emotional support for Briana during difficult personal transitions.

Zander is a nephrologist at Royaume Northwestern Hospital. He is Jacob's former roommate and one of his few established friends at the new workplace, offering advice on hospital politics and personal matters.

Jewel is Jacob's sister. She works as a tattoo artist and possesses an outspoken, highly protective personality. She frequently checks in on Jacob and is quick to jump to conclusions about his personal life.

Jeremiah is Jacob's younger brother. He began dating Jacob's ex-girlfriend just three months after their breakup, creating an awkward family dynamic heading into their upcoming wedding.

Dr. Gibson is the current head of the emergency department. By deciding to delay his retirement, he forces Briana and Jacob into an unexpected competition for his job.

Nick is Briana's ex-husband. Their ten-year marriage ended after he engaged in a lengthy affair with a mutual friend, leaving Briana deeply mistrustful of romantic commitments.

Levi is Briana's childhood friend who recently returned to town following his own divorce. Their shared history brings a sense of familiarity to Briana's stressful life.

Daniel is Alexis Grant's husband. He stays at the Grant House bed and breakfast and provides a welcoming presence when Jacob visits Briana there.

Gwen is Jewel's wife. She supports her wife's fiercely protective stance regarding Jacob's emotional well-being following his breakup.

Kelly is a former friend of Briana. She engaged in an affair with Briana's husband, Nick, which ultimately ended Briana's ten-year marriage.

Jane is one of Jacob's sisters. She is part of the large, energetic Maddox family that frequently overwhelms Jacob's social anxiety.