Correction: Hideki Sato didn't directly design all Sega's consoles, but rather oversaw their development as head of the R&D department. He was only directly involved in designing the earlier consoles.
The Saturn hardware, for example, was designed by Kazuhiko Hamada and a team of about a dozen engineers who had previously made the System 32 arcade hardware.
In addition to his work leading Sega's R&D efforts, Sato should also be remembered as one of the primary reasons why Sega began investing more into arcade video game development in the 1970s.