If only Miyamoto and Iwata really did work day and night in some giant factory, rainbows springing from the smokestacks, dreams from the delivery doors and Italian-accented laughter from the plumbing. Sadly, however, there are just too many games (and laws of physics and other such nonsense) for that suggestion to be true. Sometimes someone else has to step in and be gaming's amazing chocolateer, taking possession of Mario, The Mushroom Kingdom, or another of Nintendo's exclusive brands.
Nintendo's ever-changing family of outside developers extends far beyond the walls of their R&D studios in Tokyo, not to mention Japan's borders and all other territorial boundaries. Their search for talent takes them wherever it's to be found, and the possibilities for the chosen few are, as reigning President Satoru Iwata would be sure to tell you, practically limitless.
Iwata was himself one of Nintendo's scouted talents after all, introduced to the company through one of their earliest and most trusted second-parties, HAL Laboratory. Like many, HAL's relationship began as an experiment, their first assignment being to repair the overdue NES Pinball, which they did prior to its release in 1984. Success there led to the development of Mother for NES and Kirby's Dream Land for Game Boy, during which time Nintendo kept a close eye on the company's people and practices, analyzing the potential of both the team and their constituent members.
It's a practice that's been continued ever since, Nintendo fostering talent and recognizing enthusiasm with nary a thought, initially at least, for the potential side effects. So when HAL almost went bankrupt with a cutting-edge office expansion in 1991, plunging them into $42 million of debt, Nintendo saw through the numbers and threw them a lifeline. In return for finance and support, HAL would live on to develop titles exclusively for Nintendo platforms - while Iwata, whose persistence is credited with securing the whole arrangement, was instated as company chairman.