Fingernails

An unemployed schoolteacher who becomes an instructor at the Love Institute. She initially hides her new job from her boyfriend Ryan, and she secretly experiments with the tests to probe her own relationship. As she grows closer to Amir, she faces moral tension between professional duties and personal feelings. Her actions reveal how love can be measured and contested by data.

A fellow Love Institute instructor who guides clients through the relationship exercises and becomes drawn to Anna. He has a girlfriend, Natasha, who has also passed the test, but his growing feelings blur the line between work and romance. He displays vulnerability by engaging in the tests, even ripping out his own fingernail to comfort a client, and ultimately decides they should not be together to obey the test.

Anna's boyfriend who is unaware of the full scope of her job at first but becomes a test subject in the Love Institute's program. The couple retakes the test and passes, suggesting renewed commitment, though their relationship is stretched by the Institute's methods and the moral questions they raise about trust.

Founder of the Love Institute, a pragmatic entrepreneur convinced that relationship experiments can yield reliable truths about love. He defends the program, pushes for further research, and challenges Anna's transformative findings when she questions the possibility of two different-positive results.

Amir's girlfriend who has also passed the fingernail test. She appears in social settings with the institute and contributes to the tension around loyalty and openness in relationships, illustrating how the test affects even those who appear to be successfully 'in love'.