"Okusama ga Seito Kaichō!" centers on Hayato Izumi, a high school student who becomes the student council vice president. His life takes an unexpected turn when his childhood friend and fiancée, Rin Misumi, transfers to his school and is elected as the student council president. Rin is determined to fulfill her duties as president while also asserting her role as Hayato's fiancée, often blurring the lines between her professional and personal responsibilities. Her bold and assertive personality frequently leads to comedic and awkward situations, especially as she openly expresses her affection for Hayato in front of their peers.

The series explores the dynamic between Hayato and Rin as they navigate their roles within the student council and their complicated relationship. Rin's over-the-top antics and unwavering devotion to Hayato create a mix of humor and lighthearted drama. Supporting characters, such as the diligent and serious secretary Ai Magara and the mischievous treasurer Mei Sagara, add further depth to the story, often contributing to the comedic and romantic tension. The narrative balances school life, student council responsibilities, and the evolving relationship between Hayato and Rin, with a focus on humor and romantic misunderstandings. The series maintains a lighthearted tone, emphasizing comedic moments and the quirky interactions between its characters.