Jisai Kanemaki, a man of towering frame and stern presence, wore his long hair tightly bound, his face marked by a scar etching the left side. A missing right leg forced reliance on a walking stick, though his bearing remained dignified, clad in a pale-hued kimono with a sword bound by chains at his side. His son, Kojiro, mirrored his features with striking similarity.

Renowned for unshakable serenity and gentle resolve, Jisai weathered relentless scorn from townsfolk disdainful of his Bushi lineage. He nurtured pride in Kojiro for their ancestral legacy, imparting the significance of a Bushi’s sword as an emblem of honor. As guardian to both Kojiro and the orphaned Musashi, he trained them rigorously in martial arts and warfare, shaping them into warriors worthy of their heritage.

Fifteen years earlier, Jisai fought alongside the Uesugi band, hailed as a hero after slaying a Kishin. Esteemed even by rival factions like the Hojo Band, he later retreated into obscurity, sheltering in Tatsuyama Town to shield Musashi—the "Vessel of the Obsidian Goddess." As her "Sheath," he concealed Musashi from the Obsidian Eight until their pursuit exposed his refuge. Captured, Jisai met his end through the brutal "cow tearing punishment," a death that seared anguish into Kojiro and Musashi’s memories.

In his final moments, he extended forgiveness to Musashi for a childhood transgression—youthful insults and a hurled stone under familial coercion—an act that steeled Musashi’s dedication to Jisai’s ideals. While Kojiro grappled with disillusionment toward Bushi traditions, Musashi clung to their shared aspirations.

Jisai’s legacy endured through his sons: Kojiro’s strategic intellect and self-reliance echoed his teachings, while Musashi embodied his resolve to defend the vulnerable. Their paths, shaped by his lessons on Bushi pride and sacrifice, remained anchored in his vision as they faced trials tied to the Obsidian Goddess and the looming Kishin threat.