"Cluster" is a science fiction manga series set in a dystopian future where humanity has colonized space but faces existential threats from an alien species known as the Cluster. The story centers on Ewan, a young man living on a remote mining colony, who becomes entangled in a conflict far beyond his understanding. After a sudden attack by the Cluster, Ewan discovers he possesses a unique ability to interface with advanced alien technology, making him a key figure in humanity's survival.

The narrative explores themes of survival, identity, and the ethical implications of technological advancement. Ewan is thrust into a war against the Cluster, joining forces with a group of soldiers and scientists who seek to harness his abilities. Among them is Liza, a skilled pilot with a tragic past, and Dr. Kael, a brilliant but morally ambiguous scientist who believes Ewan’s powers could turn the tide of the war. As the story progresses, Ewan grapples with the growing realization that his connection to the Cluster may be more profound than anyone anticipated, raising questions about his own humanity.

The plot unfolds across multiple planets and space stations, with intense battles, political intrigue, and personal struggles driving the narrative forward. The Cluster, initially portrayed as a mindless, destructive force, is gradually revealed to possess a complex society and motives that challenge the human characters' perceptions. Ewan’s journey becomes a balancing act between embracing his newfound powers and resisting the potential loss of his humanity. The series delves into the consequences of war, the fragility of alliances, and the blurred lines between heroism and survival in a universe where both humans and aliens are fighting for their existence.