Megasoft

Whiteboard was a development company established in 1985, which produced arcade and home mahjong games such Mahjong Cop Ryū. The company was run by Takeshi Tozu, who had previously run Crux and Orca, and mostly did development work for SEGA. By 1989, the company's name had changed to Santos and it produced a handful more arcade and Mega Drive titles, most notably Battle Golfer Yui. The company was acquired by SEGA in December 1991, and renamed once more to Megasoft.

As a division of SEGA, Megasoft produced two titles, Aa Harimanada and Shinobi III, but the staff was soon after merged into SEGA's own internal R&D departments. After the buyout by SEGA, Takeshi Tozu left the company to establish another development studio also called Santos, which would eventually be merged into Aicom when Yumekobo was established.

Another group of former Santos staff led by Tomohiro Ishigai established Gaibrain in the early '90s.