"Blood Sucker: Legend of Zipangu" is a manga series that blends historical and supernatural elements, set in a fictionalized version of Japan's Edo period. The narrative centers on Kiyoharu, a young man who becomes entangled in a world of vampires, demons, and political intrigue after his village is destroyed by a mysterious force. Kiyoharu discovers he possesses a unique ability to absorb the powers of supernatural beings, a trait that makes him both a target and a weapon in the ongoing conflict between humans and vampires.

The story unfolds as Kiyoharu allies with a group of vampire hunters, including the skilled warrior Shizuku and the enigmatic priestess Rin. Together, they navigate a landscape where feudal lords, rogue vampires, and ancient demons vie for power. The vampires in this world are not mere monsters but complex beings with their own hierarchies, motivations, and moral ambiguities. The series explores themes of loyalty, revenge, and the blurred lines between good and evil as Kiyoharu grapples with his growing powers and the consequences of his actions.

Key antagonists include the vampire lord Raizo, who seeks to dominate both the human and supernatural realms, and the demonic entity known as the Crimson King, whose resurrection threatens to plunge the world into chaos. The plot is driven by a series of battles, alliances, and betrayals, with Kiyoharu's journey serving as the focal point. His internal struggle with his humanity and the temptations of his newfound abilities adds depth to the narrative.

The manga incorporates elements of Japanese folklore and mythology, blending them with a dark, action-packed storyline. The setting is richly detailed, with a mix of historical accuracy and fantastical embellishments that create a vivid backdrop for the characters' struggles. The series balances intense action sequences with moments of introspection, exploring the psychological and emotional toll of living in a world where survival often comes at a moral cost.