He worked for SEGA from 1990-2003 and was the man behind such hits as the Sega Rally series, Space Channel 5 and REZ. His last position was Chief Creative Officer of United Game Artists.
On September of 2003, SEGA performed an internal restructuring of its staff. Among these changes was the dissolution of United Game Artists and the transfer of its members into Sonic Team. The following month, Mizuguchi announced that he would leave SEGA on October 10, 2003. He also announced that he would freelance for the video game industry through an as-yet-unnamed company.
Tetsuya Mizuguchi maintains his own personal weblog at: http://mizuguchi.biz/