"Dragon Quest Saga: Emblem of Roto" is a three-part OVA series based on the popular "Dragon Quest" video game franchise, specifically drawing inspiration from the first three games in the series. The narrative centers on the legacy of the Hero of Roto, a legendary figure who saved the world from darkness centuries ago. The story is divided into distinct arcs, each focusing on a descendant of the Hero of Roto and their quest to uphold the family's legacy.

The first arc, "The Hero of Roto," introduces Arus, a young warrior and direct descendant of the original Hero of Roto. Arus embarks on a journey to retrieve the Emblem of Roto, a sacred artifact that has been stolen by the demon lord Baramos. Along the way, Arus encounters allies such as the priestess Mara and the warrior Dai, who aid him in his quest. The arc culminates in a battle against Baramos, where Arus must prove his worth as the Hero's heir and reclaim the Emblem to restore peace to the land.

The second arc, "The Legend of the Hero Abel," shifts focus to Abel, another descendant of the Hero of Roto, who lives in a time when the world is threatened by the evil sorcerer Hargon. Abel's journey begins when he discovers his lineage and the responsibility it entails. With the help of his companions, including the thief Tiala and the warrior Ortega, Abel sets out to defeat Hargon and his minions. This arc explores themes of destiny and courage as Abel confronts his fears and embraces his role as a hero.

The final arc, "The Adventure of Dai," follows Dai, a young boy raised by monsters on a remote island. Dai learns of his connection to the Hero of Roto when he encounters the warrior Avan, who becomes his mentor. As Dai trains to harness his latent powers, he becomes embroiled in a conflict against the demon lord Hadlar, who seeks to plunge the world into chaos. Dai's journey is one of self-discovery and growth, as he learns to balance his human and monster heritage while striving to protect the world from evil.

Throughout the series, the recurring theme of legacy is prominent, as each protagonist grapples with the weight of their ancestry and the expectations placed upon them. The narrative weaves together elements of adventure, fantasy, and heroism, staying true to the spirit of the "Dragon Quest" games. The characters' struggles and triumphs are interwoven with the rich lore of the series, creating a cohesive and engaging story that appeals to fans of the franchise and newcomers alike.