A couple, Reiko and Koji, who had promised to have no children. But Koji secretly brings along Yudou, the biological child of his lover Misaka, pretending it's a "child of a friend." After Reiko dies in her previous life, having lost everything, she awakens that day determined to take revenge. Using her old friend Masato and a fake DNA test as weapons, she skillfully manipulates Koji and Misaka's desires and suspicions, tearing them apart from within and reclaiming their wealth and lives. Five years later, the grown-up Yudou returns with a new blade, but Reiko overcomes everything and begins a new life with Masato, embracing her true self.
