"Yasuke" is a six-episode anime series set in an alternate version of feudal Japan, blending historical elements with science fiction and fantasy. The story centers on Yasuke, a real-life African samurai who served under the daimyo Oda Nobunaga in the 16th century. In this fictionalized retelling, Yasuke is a retired warrior living in seclusion after Nobunaga's fall, haunted by his past and the betrayal that led to his lord's death. His quiet life is disrupted when he encounters Saki, a young girl with mysterious supernatural powers, and her mother, who are being pursued by a powerful warlord and a group of dark forces.

As Yasuke reluctantly agrees to protect Saki, the narrative delves into his backstory, revealing his journey from being a foreigner in Japan to becoming a respected samurai. The series explores themes of honor, redemption, and the clash between tradition and modernity, as Yasuke confronts both human adversaries and supernatural entities. The warlord pursuing Saki seeks to exploit her abilities for his own gain, leading to a series of intense battles and moral dilemmas. Along the way, Yasuke encounters allies and enemies, including a group of mercenaries, a robotic priest, and a rival swordsman with a personal vendetta.

The plot intertwines Yasuke's personal struggles with the broader conflict involving Saki's powers, which are tied to a mysterious force known as the Dark Army. The series culminates in a climactic confrontation where Yasuke must confront his past, protect Saki, and face the dark forces threatening to engulf the land. Through its blend of historical inspiration and fantastical elements, "Yasuke" presents a unique take on the samurai genre, emphasizing the protagonist's internal and external battles while weaving a tale of resilience and sacrifice.