A cable between two imaginations
The idea arrived with the hardware. Tajiri told TIME that when he saw the Game Boy he was struck by its communication cable. In Tetris it carried information about falling blocks; “I thought of actual living organisms moving back and forth across the cable.” Other games used such links for head-to-head competition. He wanted information to go back and forth. Tsunekazu Ishihara, the project’s producer, told Satoru Iwata in Nintendo’s Iwata Asks interview that planning began in 1990, the year after Game Freak’s founding and the Game Boy’s release.
The design turns that cable into a reason to talk. Wild creatures appear in grass, caves and water; the player weakens one and throws a ball to catch it, then records it in the Pokédex. Red and Green each lack some creatures the other contains, so completing the record means trading with someone. A TIME history published in 2024 reports that Shigeru Miyamoto suggested the two-version split. Tajiri told TIME in 1999 that Pokémon “was made with Miyamoto-san’s advice,” and that he deliberately had defeated monsters faint rather than die; players could also give each creature its own name.
The production was small and long. Shigeki Morimoto, who wrote the battle program, said Game Freak had “only about four programmers” for Red and Green. Ken Sugimori led the character art; Junichi Masuda composed the music and programmed. Ishihara said the games were finished in October 1995, then missed the year-end sales season and came out on 27 February 1996, “the very worst time of year to release games,” on a handheld that seemed near the end of its life. He feared they had dragged the project out so long they would miss the last train. Tajiri remembered that Nintendo “didn’t expect much from the game.”
The last obstacle was memory. Morimoto recalled that the cartridge was full. When the debugging features were stripped out, about 300 bytes came free, and the team slotted in a 151st creature, Mew, even though, as Ishihara reminded him, they had been told not to touch a single bit once debugging ended. It was, Morimoto said, “a prank that everyone right up to Tajiri-san was in on.” A bug let Mew surface in some players’ games; in April 1996 CoroCoro Comic offered it to twenty winners and drew about 78,000 entries, and Ishihara recalled that afterwards weekly sales began to match what had been monthly ones. Tajiri’s 1999 account calls Mew “done on purpose”, a rumour designed to keep interest alive. Both accounts agree that a hidden creature turned the game’s exchange into rumour and trading between friends.