Pokémon Pikachu  Pokémon Pikachu, also known as in Japan, is a series of two portable "Pokémon" digital pets (similar to Tamagotchi) featuring the famous yellow electric-type Pokémon, Pikachu. Released on March 27, 1998, in Japan (November 2, 1998, in North America), it was intended as an exercise toy and mentioned by Guinness World Records as the most popular exercise toy of its time. The first release, a yellow unit resembling a Game Boy, features a black and white LCD screen used to display animations of Pikachu's activities. Gameplay differs slightly from other 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 twenty steps it counts, the Pokémon Pikachu credits its user with one watt, a virtual currency used to buy Pikachu presents. Additional activities become available as the player spends more time with their virtual Pikachu. If neglected, Pikachu will express anger and eventually refuse to recognize the player. The second release, Pokémon Pikachu 2 GS, is available in clear and silver casing with a color display featuring more animations. It features an infrared port for interacting with "Pokémon Gold", "Silver", and "Crystal" via the Mystery Gift option, which utilizes the Game Boy Color's built-in infrared communication port. This allows players to trade watts for items in the Game Boy games. 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 are not the only media franchises that are used by this Nintendo-made device. Sakura Taisen, a media franchise of SEGA 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 for the Hello Kitty franchise, licensed to Nintendo the development of the Pocket Hello Kitty. This featured a similar design to the first Pokémon Pikachu, with a game based on Hello Kitty and her friends, available 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.