Cube, sadly Ohba has left SEGA several years ago; earlier joining GungHo ent. where became director of newly created GungHo Works(already dead) and subsequently moved on march of 2010 into Premium Agency, a japanese studio where the CEO is another ex-SEGA employee who also worked at Shenmue.
Oguchi, after passing to the Sammy side of the Holding, was recently promoted, and now is Senior Managing Director, Representative Director, General Manager of R&D Group Div., besides being Director and CCO of the Holding.
Therefore, regarding these two "heads", you can put your mind at rest :cry: