An image forming apparatus comprising: a toner case containing a toner, wherein the toner case includes: a case main body having a discharge port discharging the toner; one or more rotating members (23, 24) rotatably installed in the case main body; and a following coupling connected to the rotating member (23, 24) and configured to have a pressured part, an installed member in which the toner case is attachably/detachably installed, wherein the installed member includes: a drive coupling linked to the following coupling and configured to have a pressuring part; and a drive source rotating the drive coupling, the drive coupling and following coupling are rotated in the same rotation direction around the same rotation axis by pressuring the pressured part by the pressuring part, and the pressured part is provided so as to come close to the rotation axis from an upper stream side to a lower stream side in the rotation direction, the following coupling includes: a supporting face provided perpendicular to the rotation axis; a following protrusion protruded from the supporting face and forming the pressured part; and a flange protruded from the supporting face and surrounding the following protrusion, and projection height of the flange from the supporting face is equal to or more than projection height of the following protrusion from the supporting face, characterized in that the pressuring part and the pressured part are provided so as to come into point contact with each other in a view of a direction of the rotation axis when the pressuring part pressures the pressured part. a toner case containing a toner, wherein the toner case includes: a case main body having a discharge port discharging the toner; one or more rotating members (23, 24) rotatably installed in the case main body; and a following coupling connected to the rotating member (23, 24) and configured to have a pressured part, a case main body having a discharge port discharging the toner; one or more rotating members (23, 24) rotatably installed in the case main body; and a following coupling connected to the rotating member (23, 24) and configured to have a pressured part, an installed member in which the toner case is attachably/detachably installed, wherein the installed member includes: a drive coupling linked to the following coupling and configured to have a pressuring part; and a drive source rotating the drive coupling, a drive coupling linked to the following coupling and configured to have a pressuring part; and a drive source rotating the drive coupling, the drive coupling and following coupling are rotated in the same rotation direction around the same rotation axis by pressuring the pressured part by the pressuring part, and the pressured part is provided so as to come close to the rotation axis from an upper stream side to a lower stream side in the rotation direction, the following coupling includes: a supporting face provided perpendicular to the rotation axis; a following protrusion protruded from the supporting face and forming the pressured part; and a flange protruded from the supporting face and surrounding the following protrusion, and projection height of the flange from the supporting face is equal to or more than projection height of the following protrusion from the supporting face, characterized in that the pressuring part and the pressured part are provided so as to come into point contact with each other in a view of a direction of the rotation axis when the pressuring part pressures the pressured part. a supporting face provided perpendicular to the rotation axis; a following protrusion protruded from the supporting face and forming the pressured part; and a flange protruded from the supporting face and surrounding the following protrusion, and projection height of the flange from the supporting face is equal to or more than projection height of the following protrusion from the supporting face, characterized in that the pressuring part and the pressured part are provided so as to come into point contact with each other in a view of a direction of the rotation axis when the pressuring part pressures the pressured part.