The world of psychology is far from strange to the unusual Dr. Ichirou Irabu, a resident psychiatrist of Irabu General Hospital. He and his charming nurse Mayumi run through several patients, each suffering from a mental illness that harms their everyday life. Patients should be wary of the seductive Mayumi, with her spellbinding looks and devilishly short pink nurse uniform. On the other hand, the doctor seems to have three separate personalities: a child with an oversized lab coat; an intelligent, youthful man with feminine traits; and a selfish, outgoing green bear. While curing his patients in questionable ways, Dr. Irabu often tries to gain something from them outside of his profession—and in doing so, occasionally forgets his role as a doctor. As each patient struggles to face the nature of their distress, an obvious yet invisible thread ties their paths together.

To the outside world, Hanabi Yasuraoka and Mugi Awaya are the perfect couple. But in reality, they just share the same secret pain: they are both in love with other people they cannot be with. Hanabi has loved her childhood friend and neighbor Narumi Kanai for as long as she can remember, so she is elated to discover that he is her new homeroom teacher. However, Narumi is soon noticed by the music teacher, Akane Minagawa, and a relationship begins to blossom between them, much to Hanabi's dismay. Mugi was tutored by Akane in middle school, and has been in love with her since then. Through a chance meeting in the hallway, he encounters Hanabi. As these two lonely souls spend more time together, they decide to use each other as a substitute for the one they truly love, sharing physical intimacy with one another in order to stave off their loneliness.

At Fujisaki Girls Academy, student council president Natsuo Maki is the epitome of grace and perfection, admired by all the young girls who attend the school. One day, Riko Kurahashi walks into the student council room on an errand, only to discover Natsuo practicing her kissing techniques on a pillow, an act that is neither graceful nor elegant. Riko soon discovers that Natsuo desires more romance in her life, leading her to practice romantic situations in secret. Sympathizing with her, Riko agrees to help Natsuo with her love research. Named Love Lab, the project practices the essentials of love and romance, such as bumping into each other accidentally and holding hands. Soon, the entire student council joins in on the fun in the Love Lab too! Through their research and real life encounters, what will they learn about romance? Weaving together funny characters and comedic situations, Love Lab builds a story of friendship and romance, while never missing a beat with the laughter.

Based on The Magic Tree House series, award winning series of children books written by American author Mary Pope Osborne.