 Mizuguchi worked for Japanese game publisher, Sega, from 1990 to 2003 and began his career – not on a game – but by designing arcade cabinets and an interactive 'ride' titled "Megalopolis," combining then-embryonic 3D polygonal graphics and CGI (Computer-generated imagery) with the physical experience of Sega's hydraulic 'AS-1' motion simulator.He went on to develop the acclaimed racing simulator, "Sega Rally Championship", which was influential in the racing space, inspiring future racing game franchises like "Colin McRae Rally" (another rally simulator) and the rally segments of "Gran Turismo".After forming his own division within Sega, Sega AM Annex, he continued in the racing genre with "Sega Rally Championship 2" and "Sega Touring Car Championship".