Nomura started drawing at the age of three. Nomura's father influenced his interest in art and games early on, creating little drawings.

Around high school, Dragon Warrior became Nomura's favorite because it surprised him and introduced him to video games with story elements.

In the early 1990s, Nomura was hired by Square and at first worked as a debugger for Final Fantasy IV. He received some training by artist Tetsuya Takahashi, and then design the monsters for Final Fantasy V.

In February 2000, he started working as the director of Kingdom Hearts with the production team consisting of over one hundred members from both Square and Disney Interactive.

After discussing with the Disney staff, Nomura convinced them to use original characters with him as the character designer. The game's protagonist, Sora, became his favorite character he had designed so far.