"Maryū Senki" is a fantasy anime series set in a world where dragons and humans coexist, often in conflict. The narrative centers on a young warrior named Maryū, who wields a legendary sword capable of summoning the power of dragons. Maryū is driven by a quest to avenge his family, who were killed by a rogue dragon. Along the way, he encounters various factions, including dragon clans, human kingdoms, and mercenaries, each with their own agendas and alliances.

The plot unfolds as Maryū discovers that the rogue dragon responsible for his family's death is part of a larger conspiracy involving a powerful human warlord seeking to harness dragon energy for conquest. Maryū forms uneasy alliances with other dragon slayers and sympathetic dragons, including a dragon named Ryūka, who becomes a key ally. Together, they navigate a world rife with political intrigue, betrayal, and ancient prophecies tied to the balance between humans and dragons.

The series explores themes of revenge, redemption, and coexistence, as Maryū grapples with his hatred for dragons while learning to understand their culture and history. The story is punctuated by intense battles, both physical and ideological, as characters confront their pasts and the moral complexities of their actions. The narrative builds toward a climactic confrontation with the warlord, revealing deeper truths about the origins of the dragon-human conflict and Maryū's own destiny.