"Hi sCoool! Seha Girl" is a short-form anime series that blends comedy, fantasy, and gaming culture into a lighthearted narrative. The story centers around three high school girls—Sega Saturn, Dreamcast, and Mega Drive—who are personifications of Sega's iconic gaming consoles. These characters attend a school called "Sega Hard Girls High School," where they are tasked with protecting the history of Sega by traveling through time and space to resolve anomalies that threaten the legacy of the company's gaming innovations.

The series is episodic, with each episode focusing on a specific mission tied to a different era or aspect of Sega's history. The girls use their unique abilities, which are inspired by the features of their respective consoles, to solve problems and restore balance. Sega Saturn, the cheerful and optimistic leader, represents the Sega Saturn console and often takes charge of the group. Dreamcast, embodying the Sega Dreamcast, is a cool and composed character with a strong sense of justice. Mega Drive, representing the Sega Genesis (known as Mega Drive in Japan), is energetic and tomboyish, often providing comic relief with her impulsive behavior.

Throughout their adventures, the trio encounters various characters and references tied to Sega's gaming history, including cameos from classic Sega franchises and nods to the company's real-world challenges in the gaming industry. The series balances humor with a nostalgic celebration of Sega's legacy, making it accessible to both longtime fans of the company and newcomers unfamiliar with its history. The lighthearted tone and quick pacing make it an easy watch, with each episode offering a self-contained story while contributing to the overarching theme of preserving Sega's cultural impact.