Nissin Foods Holdings Co., the company that invented instant noodles, appears to have created an entirely new category with a hit product: cup noodles made with cold water.

Initial supplies of the handy meal, available in Spicy Kimchi and Chicken Salt Lemon flavors, sold out a week after hitting store shelves on July 20, according to Nissin. While the Tokyo-based company didn’t disclose sales figures, it had anticipated supplies to last one to two months.

Nissin, which has almost half of Japan’s instant-noodle market, has long leaned on innovation to stay ahead of rivals including Toyo Suisan Kaisha Ltd. and Sanyo Foods Co. The surprise hit with Cold Cup Noodle shows the company is still able to find ways to connect with consumers with one of Japan’s most familiar convenience foods.