Ava is a 22-year-old photography student and assistant at the McCann Gallery. She lives near the Thayer University campus and has a sunny, optimistic personality that masks her lack of memories prior to age nine. She suffers from aquaphobia and frequent night terrors due to a near-drowning incident in her childhood.

Alex is the 26-year-old chief operating officer of Archer Group, a real estate company he built with his uncle. He possesses highly superior autobiographical memory (HSAM) and a genius-level IQ. Following the traumatic deaths of his parents, he maintains strict emotional boundaries and pursues casual encounters with rigid rules regarding intimacy.

Ivan is the official CEO of Archer Group and Alex's last living relative. He raised Alex following the tragic deaths of Alex's parents. He places a high value on wealth, power, and status, projecting a vain consciousness of his personal appearance.

Michael is the father of Ava and Josh. He has a chiseled face and sharp eyes. He pays for Ava's tuition at Thayer University but remains emotionally distant from her, finding it much easier to bond with his son Josh.

Josh is a popular, outgoing pre-med student at Thayer University with a perfect GPA. He lives next door to his sister Ava and serves as a sharp contrast to his best friend Alex's brooding nature. He leaves early in the story to spend a gap year as a medical volunteer in Central America.

Bridget is a Thayer University student and the princess of Eldorra, second in line to the throne. She possesses elegant bone structure and volunteers regularly at an animal shelter. She relies on her friends for normalcy while dealing with royal expectations and a strict security detail.

Jules is a confident, outgoing pre-law student with shiny red hair. She works at a highly competitive law internship and possesses a chaotic, persuasive energy. She frequently pushes her friends out of their comfort zones, including conceptualizing the plan to test Alex's emotions.

Stella is a fashion and lifestyle blogger with a massive social media following. She has a multicultural heritage and a shy, reserved personality that contrasts with her large online presence.

Liam is Ava's ex-boyfriend who struggles with substance use. Following their breakup, he refuses to accept her boundaries and frequently harasses her at social events, acting out of misplaced entitlement.

Ralph is the owner of a local Krav Maga gym and serves as Alex's hand-to-hand combat instructor. He is one of the few people who interacts with Alex on a regular, friendly basis outside of the corporate world.

Rhys is a gruff, broad-shouldered bodyguard with a jagged scar through his left eyebrow. He is assigned to protect Bridget and takes his job extremely seriously, often severely restricting her activities.

Madeline is a former casual fling of Alex's. She acts out of jealousy and vindictiveness when she notices Alex's growing interest in Ava, attempting to intimidate Ava by sharing details of Alex's unconventional sexual preferences.