Segawa continued producing serialized adaptations of Futaro Yamada's novels with The Yagyu Ninja Scrolls in 2005, Yama Fu-Tang in 2010 and Jū: Ninpō Makai Tenshō in 2012.

Additionally, a two-part novel sequel, titled Basilisk: The Ouka Ninja Scrolls, penned by Masaki Yamada with illustrations by Segawa, was published in November and December 2015.

Fast forward to the year 1614; Ieyasu has retired from power (although he still wields considerable influence within the government) and passed the torch to his son Hidetada.

Unfortunately, a succession dispute has risen concerning which of Ieyasu's grandsons are destined to take up the reins of power when their father finally decides to step down.

Each clan will represent one of the two factions supporting Ieyasu's grandsons; the names of their selected fighters recorded on two identical scrolls to be marked out in blood upon their death.

Prior to the conflicts renewal, Kouga and Iga's two young heirs (Gennosuke and Oboro respectively) were betrothed to each other in the hopes that their union would finally dispel their clans' long-seated animosity toward each other.

Forced headlong onto separate sides of a conflict they want no part of, Gennosuke and Oboro must now choose whether to kill the person they love or lead their entire clan to annihilation.