Veteran shinobi Igawa Asagi believes her days of battle are behind her after overcoming a formidable foe years ago. She seeks a quiet life with those she holds dear, including her sister who shares her path and her devoted partner. However, dark forces stir when her old enemy returns from the brink, bound by a sinister alliance with the city's chief demon. Driven by vengeance, this resurgence threatens to unravel Asagi's world, drawing her and her closest companions into a web of manipulation and peril that tests their bonds and resolve.