Olive is a 26-year-old graduate student in the Stanford University biology program. Her research focuses on the early detection of pancreatic cancer, driven by the loss of her mother to the disease. She is intelligent and fiercely dedicated to her lab work but struggles with emotional awareness and self-doubt. To ensure her best friend pursues a new relationship guilt-free, Olive initiates a mutually beneficial fake-dating arrangement with a notoriously strict professor.

Adam is a young, highly successful biology professor and researcher at Stanford. He possesses a dark, intimidating physical presence and maintains a reputation for being exceptionally harsh in his academic critiques of graduate students. Despite his terrifying campus persona, he enters into a fake relationship with Olive to convince the university he is setting down roots so they will unfreeze his research funds.

Tom is a biology professor who heads a laboratory at Harvard University. He possesses an all-American, boyish charm and a smooth, approachable demeanor that contrasts with Adam's strict personality. He expresses interest in Olive's pancreatic cancer research and offers her an opportunity to work in his lab.

Anh is a graduate student of Vietnamese descent in the Stanford biology program. She is fiercely dedicated to carving out a place for women and minorities in STEM, actively leading a campus group for BIPOC women. Her mutual attraction to Olive's ex-boyfriend causes her guilt, prompting Olive to fake a new relationship to ease Anh's conscience.

Holden is a professor at Stanford and Adam's oldest friend, having grown up alongside him. He acts as a more approachable, sociable counterpart to Adam's strict academic persona. He offers an outside perspective on Adam's personality and history.

Malcolm is Olive's roommate and one of her closest friends. He is a graduate student in the biology department who successfully balances his academic workload with a fulfilling personal life. He frequently offers Olive sarcastic but deeply supportive emotional advice.

Jeremy is Olive's ex-boyfriend. He is a friendly individual planning to enter the private industry rather than remain in academia. His brief, lackluster relationship with Olive ends amicably, and his subsequent attraction to Anh serves as the catalyst for the story's fake-dating premise.

Olive's mother passed away from pancreatic cancer when Olive was fifteen years old. Though she is not present in the current timeline, her memory heavily dictates Olive's life choices. Her death left Olive to enter the foster system and eventually become an emancipated minor.

Dr. Aslan is Olive's graduate advisor at Stanford University. Nearing retirement, she takes a highly hands-off approach to her students' work. She cultivates a supportive, healthy environment, though her extreme enthusiasm sometimes exacerbates Olive's anxiety.

Greg is a graduate student in the Stanford biology program who shares lab space with Olive. He is highly stressed by the demands of academia, particularly after receiving harsh feedback from Adam that sets his dissertation back by several months.

Chase is a graduate student working in the same Stanford biology laboratory as Olive and Greg. He serves as a polite, level-headed peer amidst the intense pressure of the graduate program.