Ten years after the war between the Iga and Kouga ninja clans ended, the two sides are expected to finally unite through the marriage of their chosen successors: Hachirou of the Kouga and Hibiki of the Iga. Both grew up knowing this duty was coming, but factions within each clan start working to sabotage the engagement before it can happen. This manga adapts the novel sequel to Basilisk: The Kouga Ninja Scrolls, following Hachirou and Hibiki as their arranged peace comes under threat from within their own clans.