The Wall Street Journal reports the nameko mushroom is taking Japan by storm—and not in the way you might expect. The mushroom, usually found in miso soup, is the star of a wildly popular smartphone game. Translated as, “The Kit for Cultivating Nameko,” the idea behind the game is simple: to grow and collect different varieties of mushrooms. Though it hasn’t reached “Angry Bird” status yet, with 32 million downloads it’s definitely hit “Big in Japan” status.