Japanese Prefecture Celebrates Pokemon 25th Anniversary With Slowpoke X Udon Collaboration Products Japanese Prefecture Celebrates Pokemon 25th Anniversary With Slowpoke X Udon Collaboration Products The Kagawa Prefecture in Japan is well known for its Sanuki Udon noodles, but Pokemon fans also know it for the association with Slowpoke. By The Kagawa Prefecture in Japan is well known for its popular Sanuki Udon noodles, but Pokemon fans also know it for the association with Slowpoke. In order to celebrate the 25th anniversary of the Pokemon franchise, a bunch of products is going to be launched as part of a collaboration between the “Udon Prefecture” and Slowpoke.