Case for an electronic device

An electronic device system comprising:

• a portable electronic device having a display screen on a front surface thereof and a connection terminal;
• and
• a case comprising:
• a main body including a first side portion, a second side portion, and a recessed portion between the first and second side portions,
• the second side portion being positionable at a first position at which a longitudinal end of the second side portion is aligned with a first longitudinal end of the first side portion and at a second position at which the longitudinal end of the second side portion is aligned with a second longitudinal end of the first side portion, and
• the recessed portion being configured to receive, therein, the portable electronic device, such that the display screen is exposed;
• a cover rotatably attached to the first side portion of the main body and configured to cover the front surface of the portable electronic device in the recessed portion when the cover is at a closed position;
• a first operation unit on a surface of the cover that faces the front surface of the portable electronic device in the recessed portion when the cover is at the closed position, the first operation unit configured to cause a first operation signal corresponding to a first user operation of the first operation unit to be transmitted to the portable electronic device through the connection terminal;
• and
• a second operation unit on an outer surface of the second side portion, the second operation unit configured to cause a second operation signal corresponding to a second user operation of the second operation unit to be transmitted to the portable electronic device through the connection terminal.