On July 14th, model-turned-singer Koo Ji Seong released her debut MV for her new single, "Bad Guy"! Produced by 015B's Jang Ho Il, "Bad Guy" is a soothing ballad with a melody that highlights the Koo Ji Seong's soft voice; it's tempered by a stylish rap from hip hop artist, Kjun. What caught the most attention, however, was her album jacket photos, which elegantly accentuate the singer's luxurious and modelesque figure. During her days as a racing car model, Koo Ji Seong was popular for her sexy curves and killer body proportions. Check out the MV for "Bad Guy" down below! Source: Enews24 via Nate Tip: Jae