Gunpei Yokoi began working at Nintendo in1965, right after he graduated from Doshisha University with a degree in electronics. He began as an assembly line worker and a janitor. During his spare time he created a extending arm, an arm that he happened to be playing with when Nintendo's president Hiroshi Yamauchi came to visit the factory. Yamauchi was impressed by the design and told Yokoi to create it as a retail product for the Christmas season. It was a huge hit and Yokoi moved from janitorial services to product development.
Yokoi spent many years developing toys for Nintendo, though once the company shifted its focus to video-game development, he was asked to develop new ideas for the burgeoning market. After seeing a businessman playing with his calculator, Yokoi conceived the Game & Watch handheld concept. The Game & Watch product line went on to feature 59 different titles, including classics like Mario Bros. and Donkey Kong. Although limited from a technical perspective, the Game & Watch is an apparent precursor to the Game Boy.
Gunpei Yokoi headed up an internal development division at Nintendo known as Research & Development 1 where, alongside Shigeru Miyamoto, he helped develop classic Nintendo titles such as Mario Bros., Donkey Kong, and Donkey Kong Jr. Research & Development 1 would go on to develop Metroid, Kid Icarus, Panel de Pon , Fire Emblem, and Battle Clash. Yokoi was also responsible for hiring Masayuki Uemura, the creator of the NES and SNES. He also created R.O.B. the robot.
In 1989, Nintendo released Yokoi's most famous creation, the Game Boy, a portable video game system that, unlike the Game & Watch, allowed players to play different games by simply swapping out cartridges. While other handheld systems of the time put an emphasis on color graphics, Yokoi insisted that quality games and good battery life should be the primary concerns. His philosophy paid off, as every other handheld system went under fairly quickly, while the Game Boy thrived.
As much success as Gunpei Yokoi experienced at Nintendo, his one major mistake would prove to be his last at Nintendo. Yokoi was one of the driving forces behind the Virtual Boy, a monochromatic video-game system that used stereoscopic screens to create a sense of depth within 2D images. Virtual reality was a popular concept at the time, and it was expected that the Virtual Boy would represent a huge leap for video games. Sadly, lackluster games and eye-straining graphics contributed to a spectacular failure for the Virtual Boy. This failure, which was followed by doubts within Nintendo of his mental stability, led to Gunpei Yokoi's resignation on August 15, 1996, ending his 31-year career with Nintendo.
Not done with the handheld video-game market, Yokoi went on to start Koto Laboratory, where, alongside Bandai, he developed the WonderSwan. Sadly, he would never see its public release.
On October 4, 1997, Yokoi and Nintendo employee Etsuo Kiso were involved in a minor accident with a truck. Kiso pulled over so they could inspect the damage, but as they did a car sideswiped them both, killing Yokoi and seriously injurying Kiso. Yokoi was 56 at the time of his death, and was posthumously awarded the Game Developers Associations Lifetime Achievement Award.