In a growing and ever-changing world of technology, start-up companies are one of the best ways to make it big as an entrepreneur. Set in a fictionalized version of Silicon Valley, "Start-Up" centres around Seo Dal-mi, a passionate and driven business owner with hopes of becoming as big as Steve Jobs. Dal-mi strives to turn her dreams into a reality, and with the help of Nam Do-san, founder of Samsan Tech, and Han Ji-pyeong, an investor, her goals soon become achievable. A love triangle between the three, however, complicates the situation, but makes it supremely entertaining to watch.