United Game Artists (UGA) was a subsidiary of Sega headquartered in Shibuya, Tokyo, Japan. It was founded by Tetsuya Mizuguchi, a video game developer who had experience with Sega's AM3 division. After separating with Kenji Sasaki to form AM Annex, Mizuguchi left Sasaki's team to form another division. This studio would later be known as Sega Consumer Development 4 (CS4) and Research and Development #9 (R&D #9, or AM9) while a department of Sega, before becoming UGA as a wholly owned subsidiary of Sega. AM Annex was created by the separation of a team from Sega AM3, which Mizuguchi described as a move to create a smaller department with a different work environment. Mizuguchi hand-selected the team that would join him at AM Annex, which worked on arcade racing game Sega Touring Car Championship. Mizuguchi later separated from Sega AM5 developer Kenji Sasaki and relocated to Shibuya, where he operated CS4/R&D #9. Later on, Mizuguchi received direction to create a game that would appeal to a broad spectrum of people, leading to development of Space Channel 5 for the Dreamcast. Along with Sega's other video game development divisions, Mizuguchi's division was separated into a wholly owned subsidiary of Sega in 2000. Mizuguchi gave his new company the name United Game Artists and was installed as CEO. United Game Artists would develop Space Channel 5: Part 2 and Rez under their moniker. In 2003, due to financial issues, United Game Artists was merged into Sonic Team, another of Sega's subsidiary companies. Mizuguchi subsequently left Sega in October of that year. Several games developed by United Game Artists are notable for their reception. Space Channel 5 is frequently credited with being a unique concept that helped bring about music-based video games. Rez is a highly well received title critically. Arcade games from AM Annex such as Sega Rally 2 have remained popular years after their release.