"My-Otome 0~S.ifr~" is a three-episode OVA prequel to the "My-Otome" series, set in the same universe but taking place years before the events of the main storyline. The narrative centers on the origins of the Otome system, a group of elite female warriors who serve as protectors and diplomats, and explores the early days of key characters who shape the future of the Otome world.

The story unfolds in the kingdom of Windbloom, where a young orphan named Sifr Fran is discovered by the royal family. Sifr possesses a mysterious power tied to the legendary "Blue Sky Sapphire," a gemstone that grants immense abilities to its wielder. Recognizing her potential, the royal family takes her in and trains her to become an Otome. Sifr's journey is intertwined with the political turmoil of the era, as nations vie for control over the powerful gemstones that fuel the Otome system.

A key figure in the narrative is Rena Sayers, a skilled Otome and mentor to Sifr. Rena's dedication to her duty and her protective nature toward Sifr highlight the bond between mentor and student. The story also introduces Bruce W. Duran, a scientist and engineer who plays a pivotal role in developing the technology that supports the Otome system. His relationship with Rena adds emotional depth to the narrative, as their shared history and mutual respect influence their actions throughout the series.

The central conflict arises when a rival nation, led by the ambitious and ruthless Schwarz, seeks to exploit Sifr's powers for their own gain. Schwarz's actions threaten the fragile peace between nations, forcing Sifr and Rena to confront the moral and ethical dilemmas of their roles as Otome. The series delves into themes of loyalty, sacrifice, and the cost of power, as Sifr must decide whether to embrace her destiny or forge her own path.

The OVA also provides insight into the origins of the Otome system's hierarchy and the creation of the GEMs, the gemstones that grant Otome their abilities. These elements lay the groundwork for the events of the main "My-Otome" series, offering a deeper understanding of the world and its characters. The narrative is driven by a mix of action, political intrigue, and character development, with a focus on the relationships that shape the future of the Otome system.

Through its exploration of Sifr's journey and the early days of the Otome system, "My-Otome 0~S.ifr~" serves as both a standalone story and a meaningful addition to the larger "My-Otome" universe. It provides context for the events and characters of the main series while delivering a self-contained narrative that highlights the struggles and triumphs of its protagonists.