소닉 어드벤처
Iizuka served as director on "Sonic Adventure", while Naka produced. One of the largest video games created at the time, the team had grown to 60 after 10 months. Sonic Team undertook development in conjunction with the Dreamcast, aiming to release the game in December 1998, even if it meant making improvements after release. Developing "Sonic Adventure" at the same time as the system, which was not completed until two months before the game's release, gave Iizuka influence over the console's development; for example, he was able to request more RAM for the console specifically for "Sonic Adventure".