A toner container for mounting in an image forming apparatus, the image forming apparatus comprising an apparatus body and a drive transmission mechanism including a first rotation portion and a second rotation portion configured to rotate in conjunction with the first rotation portion, wherein the first rotation portion includes a first connection groove having at least a portion thereof extending linearly, and the second rotation portion includes a second connection groove having at least a portion thereof extending linearly, the toner container comprising: a casing configured to be mountable to the apparatus body of the image forming apparatus, and configured to contain toner; a toner outlet formed in the casing; an opening and closing mechanism provided in the casing and configured to open and close the toner outlet; and an operation portion provided in the casing, the operation portion includes a first connection portion configured to rotate by the operation portion being operated, and configured to be coaxially arranged with and connectable to the first rotation portion of the drive transmission mechanism so as to be rotatable integrally with the first rotation portion, when the casing is mounted to the apparatus body, and the opening and closing mechanism includes a second connection portion configured to be coaxially arranged with and connectable to the second rotation portion of the drive transmission mechanism so as to be rotatable integrally with the second rotation portion, when the casing is mounted to the apparatus body, and being configured to open and close the toner outlet by the second connection portion being rotated, wherein the first connection portion is formed so as to be able to fit into the first connection groove of the first rotation portion, and the second connection portion is formed so as to be able to fit into the second connection groove of the second rotation portion. a casing configured to be mountable to the apparatus body of the image forming apparatus, and configured to contain toner; a toner outlet formed in the casing; an opening and closing mechanism provided in the casing and configured to open and close the toner outlet; and an operation portion provided in the casing, the operation portion includes a first connection portion configured to rotate by the operation portion being operated, and configured to be coaxially arranged with and connectable to the first rotation portion of the drive transmission mechanism so as to be rotatable integrally with the first rotation portion, when the casing is mounted to the apparatus body, and the opening and closing mechanism includes a second connection portion configured to be coaxially arranged with and connectable to the second rotation portion of the drive transmission mechanism so as to be rotatable integrally with the second rotation portion, when the casing is mounted to the apparatus body, and being configured to open and close the toner outlet by the second connection portion being rotated, wherein the first connection portion is formed so as to be able to fit into the first connection groove of the first rotation portion, and the second connection portion is formed so as to be able to fit into the second connection groove of the second rotation portion. includes a second connection portion configured to be coaxially arranged with and connectable to the second rotation portion of the drive transmission mechanism so as to be rotatable integrally with the second rotation portion, when the casing is mounted to the apparatus body, and being configured to open and close the toner outlet by the second connection portion being rotated, wherein the first connection portion is formed so as to be able to fit into the first connection groove of the first rotation portion, and the second connection portion is formed so as to be able to fit into the second connection groove of the second rotation portion.