The Story of Yoshiaki Koizumi: From Zelda Stories to Nintendo Switch

Koizumi Started at Nintendo with a Story for a Zelda Manual

Koizumi studied film, drama, and animation at Osaka University of Arts and planned to become a director. Unlike many of his future colleagues, he had not grown up playing video games and did not take a serious interest in them until university. That was when he became fascinated by the key difference between games and the art forms he already knew: in a film, the viewer watched a finished scene, while in a game the player was inside it and changed what happened through their own actions. The possibility of telling stories this way brought Koizumi to Nintendo, which he joined in 1991 after graduating from university.

His first assignment had little to do with programming or level design. The Legend of Zelda: A Link to the Past needed a manual that would explain the origins of the Triforce, the seven maidens, and other elements of the game. Koizumi wrote the backstory, developed the images of the three goddesses and the symbols associated with them, and then helped illustrate it all. His job was to tie separate elements of the game together with a shared story.

With the next Zelda, however, he moved from work on paper directly into game development. When Link's Awakening was still in its earliest stages and the project was essentially being carried by the personal enthusiasm of the staff, Takashi Tezuka decided to bring Koizumi in because he knew how to write stories. Koizumi delivered: he created the main storyline of Koholint Island, wrote the opening, and planned the events that unfolded during Link's journey.

At the same time, he did not try to turn the game into a film by repeatedly interrupting Link's journey with long story scenes. Most of the story was revealed through short conversations with residents, and players could miss some details entirely. This approach preserved Zelda's familiar sense of freedom: players learned as much about the world as they wanted, and the story did not stop them after every completed area.

After Link's Awakening, Koizumi stepped away from story work for a while. Nintendo was preparing to bring Mario into 3D, and his next job was to focus on how the character moved and what the player could see.

Where Will Mario Land?

Mario had previously moved across a flat level, so players could always see the distance to the next platform and roughly understand where he would land after a jump. In 3D, they had to judge more than height: the camera could look at the scene from an angle, and a platform could be not only above or below Mario but also closer to or farther away from him.

During the development of Super Mario 64, Koizumi served as an assistant director and was responsible for Mario's model, animation, and available moves. Whenever Koizumi could not work out the right movement, Shigeru Miyamoto demonstrated it himself—once, late at night, he even lay down on a table to show how Mario should swim. This gave Mario his own way of moving: he accelerated, turned, stopped, and lost his balance near edges. From the character's posture, players could tell in advance whether Mario had built up enough speed, started to slide, or moved too close to a drop.

Animation alone was not enough for precise jumping, so the developers added a clearly visible round shadow beneath Mario. It stayed directly under the character even when that kind of lighting did not look entirely natural. The shadow showed players Mario's position relative to a platform and let them adjust his direction while still in the air.

The camera was just as important. If it turned at the wrong moment, players lost their sense of direction and made mistakes even when they had judged a jump correctly. Koizumi later said that working on the camera was effectively the same as working on the game itself. Nintendo soon had to test that idea under much more difficult conditions: in a 3D Zelda, the camera had to follow not only the path ahead but also characters, objects, and several enemies at once.

Why Link Got Navi

The first experiments with a 3D Zelda began before Super Mario 64 was finished. Miyamoto initially considered a first-person view in which players would see Link only during combat. That option made the camera easier to handle, but by then Koizumi had already prepared a 3D model of the hero and wanted it to remain visible throughout the adventure. The developers settled on a third-person view and immediately faced a problem: the player had to move Link around an enemy without losing sight of the selected target.

Nintendo's developers found inspiration not in another game but at a staged sword-fighting show at Toei's studio park in Kyoto. Koizumi noticed that the hero's enemies did not attack as a group. Instead, they stepped forward one at a time, making it easy for the audience to understand whom to watch. Toru Osawa, meanwhile, noticed a fighter using a kusarigama—a sickle connected by a chain to a weight. During the fight, the man moved around his opponent as though an invisible rope connected them. Koizumi, Osawa, and other staff discussed what they had seen, and those two observations gradually became the basis of a new combat system.

The system was called Z-targeting: to select a target, the player held the Z button. Link turned toward the chosen enemy or object, while the camera tried to keep both Link and the target in view. Players could now retreat, move sideways, and attack without manually turning the character before every strike. At the same time, the developers limited the number of enemies that could attack at once, reproducing the structure of the staged fight. As a result, Z-targeting solved two problems at once: it made Link easier to control and made the action on screen easier to understand.

At first, the selected target was marked with a simple triangle so players could immediately see what Link had locked onto. But the symbol looked out of place in the game's world, so Koizumi suggested replacing it with a small fairy, and Osawa came up with the name Navi. The color of her glow showed whether Link had selected an enemy, a character, or an important object, and Navi herself could provide hints. The fairy also helped hide a Nintendo 64 limitation: from a distance, players saw only Navi's light, while the console displayed the character model itself as Link moved closer.

Koizumi's responsibilities expanded considerably on Ocarina of Time: he worked on Link's model and movement, contributed to the controls, and joined Osawa and other developers in searching for solutions to the camera and target selection. Z-targeting and Navi came out of this shared work, so it would be wrong to treat them as the inventions of a single person. Koizumi's role changed again on the next Zelda: this time he proposed an idea of his own that shaped the entire adventure.

Why a Week Became Three Days

After Ocarina of Time was completed, Eiji Aonuma was assigned to make Ura Zelda—a kind of DLC from before the era of digital downloads. The expansion, featuring harder versions of familiar dungeons, was planned for a magnetic disk on the 64DD, a drive that connected to the Nintendo 64. But Aonuma felt he had already brought those dungeons to a finished state in Ocarina of Time, so he was not interested in reworking them. Creating new locations appealed to him much more, and eventually he asked Miyamoto for permission to make a different Zelda instead. Miyamoto agreed on one condition: the new game had to be finished in roughly a year. That game became The Legend of Zelda: Majora's Mask.

With such a short schedule, reusing Ocarina of Time's existing models and program code was an obvious choice, but that alone was not enough: the new Zelda needed an idea that would keep it from feeling like the same game in a different package. Koizumi had just such an idea. At the time, he had been thinking about a separate game set in a small world where the same events repeated in a loop. At first, the player would learn what was going to happen and when; after returning to the beginning, they could be in the right place at the right time and change the course of events. When Aonuma asked him to help with the new Zelda, Koizumi suggested building the game around this concept.

The repeating cycle was originally supposed to last an entire week. But it was difficult for players to remember where every resident would be across seven days, and equally difficult for the developers to create that many connected events within the available time. So the week was shortened to three days. That was long enough to show how the town changed as disaster approached, while keeping the cycle short enough for players to remember the residents' schedules.

The three-day cycle made Majora's Mask's small world unusually dense. In the morning, one resident might leave for work; in the evening, they might meet someone close to them; and before the moon fell, they might leave town entirely. Players gradually learned these routes, intervened in events, and after returning to the morning of the first day used what they knew to choose a different path. Koizumi was responsible for the repeating time system and many schedule-based events, while Aonuma directed the project as a whole. Majora's Mask therefore had a smaller world than Ocarina of Time, but it no longer felt like a shortened copy: something new was always happening on the same streets.

Why Mario Needed Water

After Majora's Mask, Koizumi returned to Mario and co-directed Super Mario Sunshine with Kenta Usui. One of their first challenges was the same old problem of making precise jumps in 3D, and Koizumi found an unexpected solution in the new GameCube controller.

When Koizumi first held the GameCube controller, the buttons on its back reminded him of the trigger on a toy water pistol. They could be pressed gradually, and the console could tell how far the player had pushed them. Koizumi suggested giving Mario a device that sprayed water, after which the developers had to work out what such an item would look like and why the character would need it. Nintendo did not want to give Mario a weapon, so the pistol became FLUDD, a pump mounted on his back, and the setting was moved to an island that needed to be cleaned of goop.

One nozzle sprayed water downward and briefly kept Mario in the air. In Super Mario 64, the shadow helped players notice a mistake during a jump; now they had a few extra seconds to change direction and still reach the platform. The Hover Nozzle, however, created a new problem for level designers. Mario could fly over an obstacle or reach a goal by an unexpected route, so the developers had to decide which shortcuts to allow and which ones undermined the entire idea of a stage.

To keep the different locations from feeling like disconnected sets, Isle Delfino was first sculpted from clay in the shape of a dolphin. The model allowed the developers to see how plazas, bays, and mountains were positioned relative to one another, then preserve those relationships in the game itself. From the central town, players could see the amusement park, mountains, and other places Mario would later visit. This made the tropical resort feel like one coherent island rather than a collection of separate levels.

FLUDD helped players correct imprecise jumps, but it also made the controls more complicated. Players had to pay attention to Mario, the camera, and the direction of the water at the same time, while some stages took the pump away and once again demanded precise jumping on its own. Miyamoto later acknowledged that Super Mario Sunshine ended up more difficult than the developers had intended.

The Studio That Watched Players

A year after Super Mario Sunshine was released, in July 2003, Nintendo opened a new game development division in Tokyo. Takao Shimizu became the producer of its first project, with Koizumi as director. At the same time, Nintendo was preparing the rhythm game Donkey Konga and the special DK Bongos controller. The developers in the new division decided to use the drums not for keeping a beat but for controlling a character in a platformer. Their first project became Donkey Kong Jungle Beat.

Hitting the left or right drum made Donkey Kong move in the corresponding direction, hitting both at once made him jump, and clapping in front of the microphone made him attack. To build an entire game around this control scheme, Koizumi chose a side view: players did not need to control the camera, and the direction of movement was always clear. The four actions were easy to learn, so variety came not from adding more buttons but from the different ways Donkey Kong responded to combinations of those simple inputs in different situations.

At E3, Nintendo staff recorded visitors playing Jungle Beat for the first time, then studied their movements and facial expressions. If someone stopped smiling or did not understand what to do, the developers looked for the cause in the game itself. The recordings showed not only where a player got stuck, but also the exact moment they lost interest—something an ordinary bug report could not capture. By watching visitors' reactions, Koizumi checked whether the controls really were understandable from the first few minutes, just as the developers intended.

Jungle Beat was released in Japan in December 2004 and became the Tokyo division's first completed game. Afterward, the developers wanted to create a game with completely new characters, but Miyamoto suggested using one of Nintendo's existing characters for their next project. The division's next project was a new 3D Mario game, with Koizumi once again directing development. It grew out of an experiment with curved surfaces that he had led back in 2000.

How a Round Platform Became a Galaxy

For the 2000 Space World show, Nintendo prepared a technical demonstration called Super Mario 128 in which many tiny Marios ran across a round platform. Koizumi directed the demo, and what interested Miyamoto most was the platform itself: characters could move across its curved surface. At the time, however, allowing free movement across an entire sphere without players losing their sense of direction or causing problems for the camera seemed too difficult for a full game.

In 2005, after Jungle Beat, staff at the Tokyo division returned to the idea and spent three months building a prototype in which Mario was pulled toward the center of a small planet, allowing him to run across its entire surface while the camera followed. Once it was clear that the gravity system and camera worked, Nintendo began full-scale development. Space was not part of the concept from the beginning: it eventually became the clearest explanation for why separate round worlds were floating in the air and why Mario could travel between them.

The shape of the planets also solved several problems Koizumi had been dealing with since Super Mario 64. A small planet had no edge that needed to be blocked by an invisible wall: Mario could keep moving forward and eventually return to his starting point. Players were less likely to get lost, and the developers could change the rules quickly by moving Mario from an icy planet to a fiery one or reversing the direction of gravity. The round planets therefore did more than create the feeling of outer space—their shape determined how Mario moved through a level and what the player saw.

A normal jump onto an enemy's head was not enough: in 3D, it was not always easy to judge the exact landing point. Mario therefore gained a spin attack that hit nearby enemies, launched objects, and activated mechanisms.

The developers also added a way for a second player to help. Rather than controlling a separate character, the second player could point a Wii Remote at the screen, collect Star Bits, and briefly stop enemies while the first player guided Mario through the level.

Super Mario Galaxy brought together two different views of storytelling. Miyamoto believed that the story should not get in the way of Mario's fast, enjoyable adventure, while Koizumi wanted to explain the origins of Rosalina and the little Lumas. He placed the heroine's backstory in a storybook whose chapters could be unlocked separately in the observatory. Players could read them if they wanted to, but doing so was not required to finish the game. Koizumi thus returned to an approach he had used in Link's Awakening: the story was there for anyone who wanted to learn more about the world, without slowing down everyone else.

In Galaxy 2, Koizumi Took One Step Back from Development

On the first Super Mario Galaxy, Koizumi was the director and worked with the developers every day. On Galaxy 2, he became the producer: he remained one of the project's main leaders but no longer worked directly on every part of the game. The day-to-day work was divided among three directors. Koichi Hayashida brought separate ideas together into a coherent game, Takeshi Hayakawa led the programmers, and Kenta Motokura led the designers. Koizumi watched over the overall direction and joined discussions as an adviser, staying, in his own words, one step removed from hands-on development.

This division of responsibilities continued with Super Mario 3D Land for Nintendo 3DS and Super Mario 3D World for Wii U. Koichi Hayashida directed 3D Land and co-directed 3D World with Kenta Motokura. Koizumi remained the producer of both games. At the beginning of each project, he helped decide what kind of game it should be and which ideas would be left out. He then selected staff, allocated time, and stepped in wherever development began to fall behind or drift away from its chosen direction.

As a producer, Koizumi moved even further into the background: players saw the results of his work, but not the person himself. Earlier, he could personally work on a character's movement or the design of a particular system; now he helped other developers find those kinds of solutions.

From Games to an Entire Console

By the mid-2010s, Koizumi was responsible for more than Mario games. After Nintendo merged its internal divisions, he became one of the senior managers of Entertainment Planning & Development, and during the creation of Switch he served as the console's general producer. Nintendo did not publish a detailed list of the hardware decisions Koizumi personally handled, so it would be wrong to credit him with the shape of the Switch or the design of the Joy-Con. But the new title shows the scale of his work: Koizumi was now responsible not for a single game, but for the console project as a whole.

Koizumi later explained why he believed the console should come with two Joy-Con. Because it could be taken anywhere, he felt it was important to put two controllers in the box from the start. The owner could then detach both Joy-Con, hand one to another person, and begin playing together without buying anything extra.

One of the first games created for the new console was Super Mario Odyssey. Kenta Motokura directed it, while Koizumi once again worked as producer. Their goal was to surprise even people who had known Mario for many years, so the developers came up with as many unusual ideas for the series as possible and immediately tested them in the game. Mario learned to take control of enemies with Cappy and even possess a Tyrannosaurus rex, while one stop on his journey became New Donk City, populated by realistically proportioned people. These ideas were too different to fit inside one conventional world, so Odyssey became a journey through kingdoms, each with its own look and rules.

In 2017, Audiences Finally Saw Koizumi

After many years behind the screen, Koizumi finally appeared in front of the public. At the January 2017 presentation, he spoke in two roles at once: as the general producer of Switch, he introduced the new console, and as the producer of Odyssey, he presented Mario's next adventure. Today, Koizumi remains one of Nintendo's senior executives.

Koizumi did not create any of these games alone. Z-targeting emerged from the observations and discussions of several developers, Majora's Mask was made together with Aonuma, Super Mario Sunshine with Usui, and every later game had its own directors. Yet the same principle shaped Koizumi's work throughout these projects: new ideas should help the player, not get in the way.

Throughout his career, Koizumi kept returning to the same goal. In Zelda, he looked for ways to tell a story without taking freedom away from the player; in the 3D Mario games, he tried to make controlling the character and understanding the camera easier. As a producer, he began passing that approach on to other developers. And when Koizumi stepped onto the stage in 2017, many viewers saw for the first time the person whose work they had already known for years.