"Rinkan Club" is a short-form anime series that centers around the lives of high school students who are members of a unique club dedicated to exploring and discussing human anatomy and physiology. The club, known as the Rinkan Club, operates within a school setting where its members engage in humorous and often exaggerated scenarios to learn about the human body. The narrative primarily focuses on the interactions between the club members, their quirky personalities, and their comedic attempts to understand complex biological concepts.

The main characters include the club president, who is highly knowledgeable but often overly enthusiastic, leading to absurd situations. Another key member is a shy and reserved student who gradually becomes more confident through their involvement in the club. A third character, known for their eccentric behavior, frequently introduces bizarre and unconventional methods of learning, adding to the comedic tone of the series. The group is rounded out by a skeptical yet curious student who often questions the club's activities but ultimately participates in their antics.

The plot unfolds through a series of episodic adventures, each focusing on a different aspect of human anatomy or physiology. These episodes are structured around the club members' attempts to conduct experiments, create presentations, or engage in discussions, often resulting in humorous misunderstandings and exaggerated outcomes. The series balances its educational content with lighthearted comedy, using the club's activities as a vehicle to explore both scientific concepts and the dynamics of friendship and teamwork.

Throughout the series, the characters' interactions and the club's activities are portrayed in a way that emphasizes humor and absurdity, often pushing the boundaries of realism for comedic effect. Despite its comedic tone, the series occasionally touches on themes of curiosity, learning, and personal growth, as the characters navigate their high school lives and their involvement in the Rinkan Club. The narrative maintains a consistent focus on the club's activities, ensuring that each episode contributes to the overarching exploration of human biology while providing entertainment through its comedic elements.