Start-Up is a 2020 K-drama about ambitious young people chasing dreams in South Korea's fictional tech hub, Sandbox, focusing on Seo Dal-mi's journey to become an entrepreneur and her love triangle with tech prodigy Nam Do-san and sharp investor Han Ji-pyeong, who pretends to be Dal-mi's childhood pen pal, leading to complex challenges in career and romance as they build businesses and navigate the competitive startup world.