The story follows the Morality Squad of a high school, specifically its two most dedicated but least qualified members: Densuke Murai, a self-proclaimed "perverted gentleman" who holds strong ethical convictions about his own fetishes, and Masamune Natsume, the vice president of the student council who possesses almost no knowledge of sexual matters. Their mission, as they see it, is to maintain the schools moral order. However, their primary method of solving students problems involves intensely investigating a single, central question: what exactly is "H"? Each chapter of this scholarly ecchi comedy focuses on a specific erotic concept, such as underwear, breasts, the psychology of fetishes, or other related topics, which the duo then examines from biological, psychological, and experiential perspectives to reach a logical conclusion.

The series is set within a typical Japanese high school environment, though the narrative focus is almost entirely on the after-hours activities and discussions held by the Morality Squad. The tone balances detailed and often suggestive artwork of female characters with a surprisingly earnest and academic approach to discussing sexuality. The main cast includes Murai, whose role as a "perverted gentleman" means he consistently refuses easy temptations in favor of a more analytical and respectful appreciation of his interests. Natsume serves as his foil, possessing the authority to enforce the schools rules but lacking the fundamental knowledge required to do so effectively. Supporting characters include a variety of girls who embody different fetishistic archetypes, such as a gal, a track-and-field athlete, and a plus-sized otaku, each bringing their own unique "research subjects" to the group.

One notable narrative arc introduces a gal named Kuga, who holds the intimidating nickname "100-man killer cougar" due to her assumed sexual experience. However, the story reveals that Kuga has a massive secret: she is actually a virgin who knows nothing about sex. Desperate to prevent her friends from discovering the truth, she sets a honey trap to ensnare Murai, hoping to manipulate the situation to her advantage and maintain her fabricated reputation. This conflict highlights the series core dynamic, where outward appearance and internal reality constantly clash, and where even the most experienced-looking individuals may have something new to learn from the Morality Squad's unorthodox research methods.