Information about unannounced Nintendo games doesn't always slip through the cracks, but Mario Kart 9 has been a topic of discussion among multiple insiders recently. So far, multiple sources have agreed that Mario Kart 9 will focus on crossing over with other Nintendo franchises, expanding on Mario Kart 8's intersections with Animal Crossing, The Legend of Zelda, and Splatoon. Nintendo has plenty of iconic, charming franchises that could fit into Mario Kart nicely, so a crossover game wouldn't be particularly surprising. However, there's another major leaked change that hasn't gotten much attention: supposedly, item boxes will get some major adjustments in Mario Kart 9.