Chances are you've probably glimpsed or partaken in Japan's "real-life" Mario Kart. The rent-a-kart service finds locals and tourists dressing up as Mario, Peach, and Luigi and driving around the busy Tokyo streets. What's not to like? Well, turns out Nintendo itself was never a fan. Last year, the gaming giant sued the company behind the service, Marika Co., for copyright infringement. Now, a fresh ruling could derail the entire attraction.