K im Jung-youn became the world's youngest billionaire in 2022 after inheriting a fortune from her late father, Kim Jung-ju, the visionary founder of the South Korean gaming giant Nexon. Her father was a titan of the tech industry, credited with popularizing the free-to-play business model with in-game purchases, a model that now dominates the online gaming landscape. Nexon's iconic titles, such as "MapleStory" and "Dungeon & Fighter," have amassed huge global followings.

Following her father's untimely death, Kim Jung-youn and her older sister, Jung-min, inherited his stake in NXC, the personal holding company that is the largest shareholder of Nexon. This inheritance, while making her a billionaire, also came with one of the world's highest inheritance tax bills, reportedly forcing the family to pledge shares and take out loans to cover the cost. Kim Jung-youn, being a teenager at the time of her inheritance, lives a life shielded from the public eye and has no role in the management of the global gaming empire her father created.