Tati is in love with Marcelo, a guy who enjoys dating lots of girls. Honest to a fault, Tati wears her heart on her sleeve, but her intense affection only drives Marcelo further away. After attending a lecture by a young biology professor named Conrado, she decides to put his controversial theories into practice in her own love life. Conrado has developed a scientific guide to seduction, inspired by Charles Darwin's theories, comparing the dating behaviour of young people to that of animals in nature. Tati becomes his eager test subject. At first, the experiment seems to be working: Marcelo is showing interest again. But things take an unexpected turn when real feelings begin to spark between the professor and the student.