Japan is going to get a limited edition Pokkén Tournament Pro Pad controller. Hori has announced a Pikachu variation that’s bright yellow with black trim and has a Pikachu silhouette emblazoned on it. [Thanks, Serebii!]
Currently, the Pikachu Pokkén Tournament Pro Pad is set for a June release in Japan, though an exact date has yet to be announced. It will be ¥3,758 (~$34). To compare, the standard Pokkén Tournament Pro Pad is $24.99. These controllers are region-free, so it would be possible to import the Pikachu version of the Pro Pad and use it on your North American or European Nintendo Wii U.
Pokkén Tournament is immediately available for the Nintendo Wii U.