Hironobu Sakaguchi co-founded Square with Masafumi Miyamoto in September of 1983. Their first games were very unsuccessful, so with no other choice, the pair decided to conclude their stay in the game industry by creating one title with the rest of Square's available funds. They called it: Final Fantasy. The game was released in Japan for the Famicom (also known internationally as the Nintendo Entertainment System) on December 18, 1987 and became an instant hit across Japan. This, of course, surprised Sakaguchi-san, who decided to delay his retirement. Final Fantasy developed into a successful franchise under his watchful eye, and now spans from stand alone stories to spin-offs and direct sequels. After directing every title in the flagship series through Final Fantasy V) for the Super Famicom, he took on the role of executive producer for the series, along with producing many of Square's other game projects.

Sakaguchi has enjoyed a distinguished career in game development with his titles selling over 80 million units worldwide. A long-time proponent of bringing together the story-telling tradition of film and the interactive elements of games, he took on the directorial role on Final Fantasy: The Spirits Within, an animated motion picture loosely based on previously established Final Fantasy series themes. Unfortunately, the movie was a catastrophic financial failure, the second-biggest animated box office bomb in cinema history, losing over $120 million and leading to the closure of Square Pictures. The upset, for which Sakaguchi was responsible, affected Square's financial capital, and may well have precipitated the merger with rival role-playing game creator Enix. As a consequence, feelings towards Sakaguchi's tenure at Square are somewhat mixed.

In 2000, Sakaguchi became the third person inducted into the Academy of Interactive Arts and Sciences' Hall of Fame. After voluntarily resigning from Square, he founded the game development studio Mistwalker with the financial backing of Microsoft Game Studios. In February of 2005 it was announced that Mistwalker would be working with Microsoft Game Studios to produce two role-playing titles for the Xbox 360 game console. Nevertheless, despite Microsoft's financial backing, Mistwalker remains independent of console exclusivity. Apart from Blue Dragon and Lost Odyssey, Sakaguchi is also producing Archaic Sealed Heat for Nintendo DS. He has at least three more titles planned for Nintendo game consoles.