Production thumb|right|upright|Tetsuya Mizuguchi in 2007 Rez was developed by United Game Artists, an internal studio of Sega led by Tetsuya Mizuguchi, who was then known for his work on racing games. The original concept for Rez originated between 1994 and 1995. During research work in Europe on Sega Rally Championship 2, Mizuguchi and a few friends attended the open-air music event Street Parade. Seeing people swaying en masse to the music, he decided that this was the type of game he wished to make. At this time, the technology was inadequate for realising his vision. In 1998, Mizuguchi was approached about forming a dedicated team to work on new innovative titles for Sega's new Dreamcast console; his first project along these lines was Space Channel 5, and during its production he made plans for Rez. He built up his new team at what would become United Game Artists. As with Space Channel 5, Mizuguchi wanted to draw in casual gamers from across demographics, along with people who would normally not play games. He had great difficulty pitching the game to Sega, as he found it difficult to explain what Rez was until they played the prototype.
Production thumb|right|upright|Tetsuya Mizuguchi in 2007 Rez was developed by United Game Artists, an internal studio of Sega led by Tetsuya Mizuguchi, who was then known for his work on racing games. The original concept for Rez originated between 1994 and 1995. During research work in Europe on Sega Rally Championship 2, Mizuguchi and a few friends attended the open-air music event Street Parade. Seeing people swaying en masse to the music, he decided that this was the type of game he wished to make. At this time, the technology was inadequate for realising his vision. In 1998, Mizuguchi was approached about forming a dedicated team to work on new innovative titles for Sega's new Dreamcast console; his first project along these lines was Space Channel 5, and during its production he made plans for Rez. He built up his new team at what would become United Game Artists As with Space Channel 5, Mizuguchi wanted to draw in casual gamers from across demographics, along with people who would normally not play games. He had great difficulty pitching the game to Sega, as he found it difficult to explain what Rez was until they played the prototype.