"How to Become Ordinary" centers on a high school student named Haruto Soma, who lives in a world where extraordinary abilities are commonplace. Despite being surrounded by peers with unique powers, Haruto possesses no special talents, making him an anomaly in his society. The narrative explores his journey to navigate a world that values the exceptional, as he strives to find his place and redefine what it means to be "ordinary."

The story begins with Haruto enrolling in Astrum Academy, a prestigious institution for students with extraordinary abilities. His lack of powers makes him a target for ridicule and exclusion, but he remains determined to prove that being ordinary does not equate to being insignificant. Along the way, he befriends a diverse group of classmates, each grappling with their own struggles despite their extraordinary gifts. These include Kaito, a prodigy burdened by expectations; Aoi, whose powers come with a dangerous side effect; and Rina, who hides her insecurities behind a facade of confidence.

As the series progresses, Haruto's resilience and resourcefulness begin to influence those around him. His ability to solve problems through ingenuity and teamwork, rather than relying on powers, earns him the respect of his peers. The plot delves into themes of self-worth, societal pressure, and the value of individuality, as Haruto challenges the notion that extraordinary abilities are the sole measure of success.

The narrative also introduces an overarching mystery involving the origins of the students' powers and the true purpose of Astrum Academy. Haruto and his friends uncover hidden truths about the institution, leading to conflicts with authority figures and rival factions. The series balances slice-of-life moments with action-packed sequences, as the characters face both personal and external challenges.

By the end of the series, Haruto's journey comes full circle as he redefines the concept of being ordinary, demonstrating that true strength lies in embracing one's uniqueness and finding value in the seemingly mundane. The story concludes with a sense of closure, while leaving room for further exploration of its richly developed world and characters.