It is believed that Sega of Japan began planning for a 32-bit console in the early 1990s with plans drawn up in 1992. The main console plan that can be directly related to the final outcome was the Sega Giga Drive. This name was given to it as a wordplay on the Sega Mega Drive, implying that this new console is more powerful.
The Giga Drive was Sega's first dedicated CD-ROM based console (not like Mega CD which was an add-on for Mega Drive). It was also their first dedicated 32-bit console (not like the 32X which was also an add-on for Mega Drive). The Giga Drive was developed by Hideki Sato and his team of engineers. It was being designed around 1992-1993 to be superior to the 3DO Interactive Multiplayer. It is believed that prototypes were made during 1993. Also at this time, the name was changed to Sega Saturn, named after the planet like other Sega projects (The "Planet Projects").
The Saturn that eventually made it to the market in 1995 was different to the one conceived in 1993. It was originally going to be the ultimate 2D console with 3D capabilities being a possibility. Sega's Virtua Fighter arcade game had become very popular and gamers hoped that Sega would have 3D capabilities in their new console so that Virtua Fighter could be ported for play on it. In November 1993, Sony announced their entry into the console market with the PlayStation under development. These factors, mainly the latter, are what made Sega change the specs of their system to become the more powerful console we know today.