"Love Lab" centers around the lives of students at Fujisaki Girls' Academy, a prestigious all-girls school known for its disciplined environment. The story begins when Riko Kurahashi, a tomboyish and athletic first-year student, accidentally discovers that the school's seemingly perfect student council president, Natsuo Maki, is secretly practicing romantic gestures in a hidden room. Natsuo, despite her outward appearance of grace and maturity, is inexperienced in love and resorts to creating elaborate scenarios to prepare for a future relationship. Riko, initially shocked by this revelation, becomes entangled in Natsuo's experiments after being blackmailed into secrecy.

As the series progresses, Riko and Natsuo form an unlikely partnership, with Riko providing practical advice based on her observations of her older sister's relationship. Their interactions attract the attention of other members of the student council, including the cheerful and energetic Suzune Tanahashi, the stoic and analytical Eno Shibasaki, and the shy and reserved Ayano Sakurai. Together, the group engages in various comedic and heartfelt activities, ranging from creating a "love lab" to study romantic behavior to navigating the complexities of friendship and personal growth.

The narrative explores themes of friendship, self-discovery, and the awkwardness of adolescence, often blending humor with moments of sincerity. Each character brings a unique perspective to the group, contributing to the dynamic and often chaotic situations they find themselves in. Natsuo's earnest but misguided attempts to understand romance serve as a driving force for many of the series' comedic moments, while Riko's grounded personality provides a counterbalance to Natsuo's over-the-top antics.

Throughout the series, the characters' relationships deepen, and their individual quirks and insecurities are revealed. The story maintains a lighthearted tone, focusing on the everyday lives of the students and their humorous misadventures. While romantic elements are present, the series primarily emphasizes the bonds of friendship and the process of growing up, making it a relatable and entertaining portrayal of teenage life.