"Attack on Titan: No Regrets" is a two-part OVA series that serves as a prequel to the main "Attack on Titan" storyline, focusing on the backstory of Levi Ackerman, one of the franchise's most prominent characters. The narrative delves into Levi's life before joining the Survey Corps, exploring his origins and the events that shaped his character.

The story begins with Levi living in the Underground City, a grim, impoverished area beneath the surface where the wealthy elite reside. Levi, along with his close companions Isabel Magnolia and Furlan Church, survives by engaging in theft and other illicit activities. Despite their harsh circumstances, the trio dreams of escaping to the surface and living a life of freedom. Their opportunity arises when they are apprehended by Erwin Smith, the future commander of the Survey Corps, who offers them a deal: join the military and assist in a covert mission in exchange for their freedom.

Levi and his companions reluctantly agree and are integrated into the Survey Corps. The mission involves investigating and eliminating a corrupt noble who has been embezzling military funds. As Levi and his team navigate the complexities of military life and the dangers of Titans, tensions arise between their personal goals and the expectations of the Corps. Levi's exceptional combat skills quickly draw attention, but his reluctance to conform to military discipline creates friction with Erwin and other officers.

The narrative intensifies as the mission unfolds, revealing the harsh realities of the world above ground. Levi's loyalty to his friends is tested, and the brutal consequences of their actions become apparent. The story highlights Levi's internal struggle between his desire for freedom and his growing sense of responsibility toward humanity's survival. The OVA series provides a deeper understanding of Levi's motivations, his relationship with Erwin, and the events that ultimately lead him to become a key figure in the fight against the Titans.

"Attack on Titan: No Regrets" offers a concise yet impactful exploration of Levi's character, shedding light on his origins and the formative experiences that define his role in the larger narrative of "Attack on Titan." The series complements the main storyline by providing context for Levi's actions and relationships, making it a valuable addition for fans seeking a deeper understanding of the franchise's lore.