A liquid storage container unit according to the present invention includes: a liquid storage container provided with an opening; a plug which is attachable to and detachable from the opening and provided with a front edge to be inserted in the opening; and a support member which connects the plug and a member other than the plug and supports the plug, wherein the support member is molded into a shape with a curved portion and the front edge of the plug comes closer to the inner side surface of the curved portion of the support member in a state in which the plug is removed from the opening than in a state in which the plug is attached to the opening.