From Wikipedia
Amusement Vision, Ltd. is a former Japanese video game developer formerly known as Sega AM4. AM4 was a special research department of Sega known for the development of arcade games such as Daytona USA.
Amusement Vision was formed in 2000 and was then considered to be a second-party developer to Sega. In July 1, 2004, Amusement Vision and Sega's other subsidiaries, Sega Wow, Hitmaker, Smilebit, Sega Rosso, Overworks and United Game Artists reintegrated into Sega following the merge between Sega and Sammy in 2005, and a holding company, (Sega Sammy Holdings), was formed. The subsidiaries ceased to exist and were renamed.