To allow users who usually play games on a personal computer to enter input to game consoles for domestic use without being stressed.A controller system for game consoles is made up of a game console controller 100 and a mouse 200. The mouse 200 is identical to an ordinary mouse. The game console controller 100 has a structure resembling a part of a keyboard that is used for common personal computers and equipped with at least six keys 120 in a 2-by-3 array. The mouse 200 and the game console controller 100 can be attached to and removed from each other via a cable 210 extending from the mouse 200. The connection between them is an USB connection.