Audiences around the world know him as Yoo Ah-In, but that's actually the 28-year-old actor's stage name. In a 2013 interview with SBS Radio, Ah-In recounted how his first manager wanted to create a stage name fit for a Korean idol, and that his government name, Uhm Hong-sik, was considered to be old-fashioned and not befitting of a young new star. "The stage name 'Yoo Ah-in' was coined together with my manager," he said. "[Ein] means 'one' in German." Even though his stage name is Yoo Ah-In, you can still find him on Instagram as "Hong-sick."