Pokémon Pikachu, also known as Pocket Pikachu (ポケットピカチュウ?) in Japan, is a series of portable Pokémon digital pets featuring the famous yellow electric Pokémon, Pikachu. This product was intended as an exercise toy and mentioned by Guinness World Records as the most popular exercise toy of its time. The first release of the device was simply called "Pokémon Pikachu." A yellow unit resembling a Game Boy, it features a black and white LCD screen used to display animations of Pikachu's activities. The second release, Pokémon Pikachu 2 GS, was available in clear and silver casing with a color display featuring more animations. Both of the Pokémon Pikachu incarnations differ slightly from more traditional portable virtual pets in that Pikachu does not need to be fed, watered, or cleaned up after. Instead, the Pokémon Pikachu unit can be strapped to a belt and used as a pedometer. With every step it counts, the Pokémon Pikachu credits its user with "watts," which are a sort of currency used to buy Pikachu presents. About twenty steps on the pedometer will reward the player with one watt. As the player grows closer to Pikachu, more activities become available. However, if neglected, Pikachu will become angry and eventually refuse to recognize the player. Pokémon Pikachu 2 GS features an infrared port for interacting with Pokémon Gold, Silver, and Crystal via the Mystery Gift option, which uses the Game Boy Color's built-in infrared communication port. This mode allows players of the Game Boy titles to trade their Pokémon Pikachu's watts for items to use in the Game Boy game. Although there is a limitation on how much the Mystery Gift mode can be used between Game Boy cartridges, Pokémon Pikachu's only limit is that of available watts. Watts can also be sent to other Pokémon Pikachu 2 units.
Pokémon and its character, Pikachu were not the only media franchises that were used by this Nintendo-made device. Sakura Taisen, a media franchise ofSEGA and licensed by RED Entertainment released a virtual-pet with pedometer in the same style as the Pokémon Pikachu 2 called Pocket Sakura (ポケットサクラ). It was released alongside Sakura Taisen GB, they were developed by Jupiter. Sega could not publish either of them because they were rivals at the time with Nintendo, so publishing was handled by Media Factory.
Similarly, Sanrio, responsible of the Hello Kitty franchise licensed to Nintendo the development of the Pocket Hello Kitty, which was a version of the first Pokémon Pikachu, just with different software/game, this time based in Hello Kitty and her friends and in a pink colored case.
A device similar to the Pokémon Pikachu, called the Pokéwalker, comes packaged with Pokémon HeartGold and SoulSilver and communicates directly with the game cards via infrared. It allows the player to transfer one Pokémon at a time from their HeartGold or SoulSilver. The user is able to catch Pokémon and find items by spending watts.