"President Momoi Kun" centers on Momoi, a young boy who unexpectedly becomes the president of a major corporation after his father, the previous president, passes away. Despite his age, Momoi is thrust into the high-stakes world of corporate leadership, where he must navigate complex business decisions, rival companies, and internal power struggles. The series explores his journey as he balances the responsibilities of his new role with the challenges of being a child in an adult-dominated environment.

Momoi is supported by a group of loyal employees, including his secretary, who acts as a mentor and guide, helping him adapt to his new position. The narrative delves into themes of leadership, resilience, and the clash between innocence and the cutthroat nature of the business world. As Momoi grows into his role, he faces various obstacles, from corporate espionage to ethical dilemmas, all while trying to maintain his integrity and youthful perspective.

The manga blends elements of comedy, drama, and slice-of-life, offering a unique take on the corporate genre through the lens of a child protagonist. The characters are diverse, ranging from supportive allies to cunning adversaries, each contributing to the dynamic and often unpredictable nature of the story. Through its engaging plot and character development, "President Momoi Kun" provides a fresh perspective on leadership and the complexities of the corporate world.