Legal Question in Business Law in California

Re: How to seek permission to write a script on a copywrited object

The game itself should contain copyright notices stating who owns the rights; this notice is probably on the packaging in which the game is sold and probably also appears on screen when the game boots up. It may also appear on the cartridge.

The copyright holders identified in these notices are probably the people you will need to negotiate with and should be the first people you contact. There may be others you will have to deal with if the game is based on characters someone else had created previously or if the rights have been sold to a third party.

The fact that the game runs on a Sony machine is probably not enough to give Sony rights to the characters and story, unless the company itself created the game or insisted on receiving such rights as a condition of licensing its technology to the game's creators. Sony surely has rights to some of the hardware and software that makes the game run, but those rights would probably be irrelevant to your project.