"Seitokai no Ichizon" centers on the student council of Hekiyou Academy, a prestigious private school where council members are elected based on popularity rather than academic merit. The council is composed of four girls and one boy, Ken Sugisaki, who is the only male member and serves as the council’s secretary. Ken, a self-proclaimed "harem protagonist," often humorously claims that his presence in the council is part of a grand plan to create a romantic harem scenario, though his antics are largely played for comedic effect.

The narrative unfolds primarily within the confines of the student council room, where the members engage in lighthearted banter, discussions about school life, and occasional problem-solving. Each member brings a distinct personality to the group: Kurimu Sakurano, the council president, is a petite and energetic girl with a love for sweets; Minatsu Shiina, the vice president, is a calm and mature figure who often mediates conflicts; Chizuru Akaba, the treasurer, is a stoic and intelligent girl with a sharp tongue; and Mafuyu Shiina, the secretary, is Minatsu’s younger sister, who is shy and reserved but deeply caring.

The series blends slice-of-life comedy with meta-humor, frequently referencing otaku culture, visual novels, and other anime and manga tropes. Ken’s over-the-top declarations about harem dynamics and his interactions with the other members drive much of the humor. Despite his comedic obsession with creating a harem, the relationships between the characters remain platonic, with moments of genuine camaraderie and friendship.

Episodic in nature, the story explores various school-related scenarios, such as organizing events, addressing student concerns, and navigating interpersonal dynamics. The council members often find themselves in absurd or exaggerated situations, but these are balanced by moments of heartfelt connection and growth. The series maintains a lighthearted tone, with occasional forays into more serious themes, such as the pressures of leadership and the challenges of balancing personal and academic responsibilities.

"Seitokai no Ichizon" is characterized by its witty dialogue, self-aware humor, and ensemble cast dynamics. The interplay between the characters, particularly Ken’s comedic attempts to fulfill his harem fantasy and the other members’ reactions, forms the core of the narrative. The series offers a humorous and engaging look at student council life, blending comedy, friendship, and a touch of otaku culture.