Kim Namjoon, feared and respected as the most merciless mafia boss in town, built his empire on blood, loyalty, and power. But behind his ruthless reputation lies a secret-he once had a sister who vanished from his life years ago. When fate finally leads him to her, Namjoon prepares himself to meet a broken, lonely girl in need of saving. Instead, he is left speechless. Nayoung, just sixteen, has already defied every odd-skipping grades, entering college early, and thriving on her own with brilliance and independence. She isn't the fragile shadow he expected but a young woman blazing through life with a strength that surprises even him. Now, Namjoon faces a battle more complicated than any war in the underworld: should he step into her world and risk tainting it with his darkness, or quietly watch from afar, letting her shine without his shadow? A tale of bloodlines, choices, and unexpected family bonds-will the feared mafia boss learn how to be a brother again, or will he walk away before his presence destroys the only pure thing left in his life? "Blood runs as smooth as velvet, but strikes as sharp as violence." Started: December 15, 2025 Ended: January 30, 2026