Abstract: A backpack for use alone or in conjunction with a hiking or book backpack where the backpack includes a plurality of storage compartments, a main storage compartment, a first side storage compartment and a second side storage compartment. A top opening of the main compartment is accessed via the opening and closing mechanism to allow the user access to the interior volume of the main storage compartment when in a horizontal orientation and a top opening of the first compartment is accessed via the opening and closing mechanism of the first compartment, which is positioned at the top of the first compartment when the flexible backpack system is positioned in the vertical position and from the side when in the horizontal position.