Samojirou Aboshi serves as the primary antagonist opposing the eight Dog Warriors. He is a powerful demonic entity determined to prevent the reunification of these eight reincarnated souls, destined to defend the Awa/Satomi clan. His actions stem from the corrupt feudal lords of the violent Sengoku era, who prioritized selfish needs over others amidst political instability and warfare.

Aboshi actively manipulates events to keep the Dog Warriors separated and forces them into mortal combat against each other. His tactics involve psychological torment, leading the warriors through nightmare-laden journeys where reality and illusion blur, exploiting the tragic pasts each carries. These tragic origins trace back to the unnatural union between Princess Fuse of the Satomi clan and a demon-possessed dog during a period of clan desperation against rival forces backed by demonic power; their killed unborn offspring reincarnated as the eight Dog Warriors.

His manipulation extends beyond the warriors to exploit the era's social and political corruption, including feudal lords killing to maintain their image or families arranging marriages for status or money. Aboshi's ultimate goal is to stop the warriors from uniting to fulfill their destiny: redeeming their clan and confronting the demonic forces threatening it. The narrative culminates as the eight Dog Warriors overcome Aboshi's schemes, gradually find one another despite his efforts, and finally unite, embodying the eight bushido virtues for a final confrontation to defeat him and his demonic influence.