"Ebiten: Ebisugawa Public High School's Tenmonbu" is a comedic anime series centered around the eccentric members of the Astronomy Club at Ebisugawa Public High School. The club, officially known as the Tenmonbu, is a small and quirky group of students who spend their time engaging in bizarre activities rather than actual astronomy. The club's president, Itsuki Noya, is a self-proclaimed genius who often devises strange experiments and schemes, while the vice president, Kyouko Toshinou, is a lazy and apathetic girl who frequently clashes with Itsuki. The club also includes Izumiko Suzuhara, a shy and reserved girl who often finds herself caught up in the chaos, and Touka Ookami, a transfer student with a mysterious past who joins the club out of curiosity.

The series primarily focuses on the daily antics of the Tenmonbu members as they navigate school life, interact with other students, and deal with the absurd situations that arise from their unconventional activities. The club's misadventures range from attempting to summon aliens to creating bizarre inventions, often leading to comedic misunderstandings and over-the-top scenarios. The interactions between the characters are driven by their contrasting personalities, with Itsuki's over-the-top enthusiasm clashing with Kyouko's laid-back attitude, while Izumiko and Touka provide a balance of innocence and intrigue.

Throughout the series, the Tenmonbu members encounter various side characters, including other students and faculty members, who often become unwitting participants in their schemes. The humor is largely derived from the exaggerated reactions and absurdity of the situations, with a focus on slapstick comedy and wordplay. Despite the lack of a central overarching plot, the series maintains a lighthearted and episodic structure, with each episode presenting a new set of comedic challenges for the club to overcome. The narrative thrives on its chaotic energy and the dynamic between the characters, making it a straightforward and entertaining slice-of-life comedy.