敵は本能寺にあり
The plot is based on the novel "Akechi Samanosuke no Koi," the final work in a trilogy by Hiroshi Kato about the forced suicide of Oda Nobunaga at the temple Honnoji. Historically, the general Akechi Mitsuhide is credited with causing Nobunaga's downfall. Kato's novel focuses on Mitsuhide's nephew Samanosuke, who fought alongside his uncle during the assault on Honnoji.