Sesshōmaru, firstborn son of the Great Dog Demon Tōga and Lord of the Western Lands, began his journey characterized by arrogance and disdain for humans and half-demons. He relentlessly pursued greater power and sought to claim his father's sword Tessaiga from his half-brother Inuyasha, losing his left arm in their first major conflict; this injury endured until his demonic power regenerated it centuries later. His path involved confronting the manipulative Naraku, who offered him a temporary human arm embedded with a Shikon Jewel shard, though Sesshōmaru ultimately sought Naraku for personal vengeance.

A pivotal transformation began with the human orphan Rin. After wolves mauled her while she aided him, Sesshōmaru used Tenseiga—the sword inherited from his father that revives the dead—to save her life, marking the awakening of his capacity for compassion. Rin's unwavering loyalty and Tenseiga's lessons gradually softened his contempt for humanity, leading him to protect her and accept her companionship alongside his retainer Jaken and the two-headed dragon A-Un. His mother later reinforced this growth, emphasizing life's fragility and warning that Rin could not be revived again should she die.

By *Inuyasha: The Final Act*, Sesshōmaru embraced his role as a protector, acknowledging his father's wisdom in bequeathing Tenseiga. He developed the Meidō Zangetsuha technique and regenerated Bakusaiga, a sword symbolizing his acceptance of his path. After Naraku's defeat, he married the adult Rin, and they had twin half-demon daughters, Towa and Setsuna. When Zero—sister of the beast demon Kirinmaru—targeted his family due to a prophecy involving half-demons, Sesshōmaru orchestrated protective measures: he hid Inuyasha and Kagome within the Black Pearl, entrusted their daughter Moroha to the Wolf-Demon Tribe, and concealed his own daughters near the Sacred Tree of Ages. During a forest fire instigated by Kirinmaru, Towa was sent through the tree to modern-day Tokyo, while Setsuna remained in the feudal era under the care of the demon slayer Kohaku.

Throughout *Yashahime*, Sesshōmaru operated from the shadows, monitoring his daughters' journeys. He intervened at critical moments, severing the Dream Butterfly to restore Setsuna's ability to sleep and gifting the broken Tenseiga to Towa after Zero destroyed it. He also supported the twins and Moroha in confronting Kirinmaru and Zero to break the Silver-Scale Curse threatening Rin's life, balancing protection with allowing the next generation to forge their own strength. This culminated in Kirinmaru's defeat and Rin's revival. Following these events, he continued his nomadic existence while remaining a guardian to his family.