OVA
Description
Hikage, a skilled ninja of the Takeda clan, shares a deep childhood bond with Marou, forged in memories of shared fields. This bond shatters when Marou, succumbing to emerging demonic traits, attacks Hikage and abandons the clan. After clan leader Shingen Takeda is slain by a yōma, Hikage is tasked with hunting down Marou to protect the clan's weakness.

His mission leads him to a village plagued by memory loss, manipulated by a spider yōma disguised as a priest. There, he meets Aya, a woman bearing a facial scar who becomes a significant connection. Despite his primary goal, Hikage protects Aya and the villagers. Defeating the spider yōma restores the villagers' traumatic memories, driving them to mass suicide; Aya drowns herself, deepening Hikage's survivor guilt and fueling his resolve to confront Marou, now the demon lord Kikuga no Miko.

Two years later, Hikage pursues Marou across war-torn lands. He encounters another young kunoichi named Aya, marked by a similar scar, who becomes his companion. She faces threats like Kōga ninja and the sea demon lord Majuumi no Miko, often needing Hikage's aid. Their journey exposes widespread demonic influence, including villages reanimated as corpses. Hikage battles yōma like the serpent Shiratsuyu and the tree-embedded Yōki, wielding explosive "nageteppo" grenades and a distinctive claw gauntlet.

Hikage faces betrayal when former comrade Kazami attacks him under orders from the new Takeda leader but deliberately loses. Kazami's dying revelation exposes Marou manipulated the clan into the doomed battle at Nagashino, severing Hikage's last ties. Ignoring the second Aya's pleas to abandon his quest, Hikage confronts Marou/Kikuga. Marou rationalizes his demonic existence as freedom from human limits and offers Hikage power, who defiantly rejects both the offer and the concept of destiny.

After defeating the fused Kikuga and Majuumi, the spirit Kotone reveals Marou killed her during an earlier loss of control. She reincarnates Marou as a human infant. Hikage retrieves the child, a symbol of cyclical hope for redemption, and departs with the second Aya to raise him.

Hikage excels in precise ninja tactics over supernatural abilities. A scar under his right eye, from Marou's poisoned shuriken, marks their fractured bond. His journey embodies persistence against despair, loyalty to humanity, and the burden of loss, defined by his relationships with both Aya women and his unresolved grief over Marou's corruption.