An image forming apparatus includes: a detection unit configured to detect an amount of developer stored in a developing container and to output remaining amount information; and a control unit configured to perform control, during a replenishment of the developer to the developing container using a replenishment container, to cause a display unit to display a message related to the replenishment. When the replenishment is instructed, the control unit is further configured to perform a first control during the replenishment in a case where the remaining amount information indicates a first remaining amount, and configured to perform a second control different from the first control during the replenishment in a case where the remaining amount information indicates a second remaining amount greater than the first remaining amount.

A toner container includes a bag body, a coupling member, and a discharge member. The bag body includes a side portion and has, formed in the bag body, storage space configured to store toner and having flexibility. The coupling member is coupled with an opening of the bag body. The discharge member discharges the toner stored in the storage space. The side portion extends in a first direction from the opening to a bottom portion opposite the opening. Two-dimensional code is provided on an outer surface opposite an inner surface of the side portion that forms the storage space for toner. The two-dimensional code is located closer to the bottom portion than to the opening in the first direction.

A development unit includes a development housing configured to store toner and a development roller rotatable about a development axis extending in a first direction. The development roller supplies the toner in the development housing to a photosensitive drum. The development housing includes a reception port and a slope. The reception port receives toner from a toner container configured to store the toner to be supplied to the development housing. The reception port is located away from the development roller in a second direction crossing the first direction. The slope is located below the reception port in the development housing. The slope includes a first slope portion and a second slope portion. The first slope portion is inclined downward away from the reception port in the first direction. The second slope portion is inclined downward toward the development roller in the second direction.

A toner housing extends in a first direction. The toner housing stores toner. The toner housing includes a reception portion and a discharge port. The reception portion is located at an end surface of the toner housing at one end in the first direction. The reception portion has a reception port for receiving toner into the toner housing. The discharge port is located between the one end of the toner housing and an other end of the toner housing in the first direction. The discharge port is located on a surface crossing the end surface. The discharge port is for discharging toner in the toner housing. A reception shutter is attached to the reception portion. The reception shutter is movable between a reception shutter closed position at which the reception port is closed and a reception shutter open position at which the reception port is open.

A toner pack storing a toner is provided in which the toner comprises a first toner particle and a second toner particle, a portion formed by connecting a plurality of protrusions comprising silicon is present on the surface of the second toner particle, the content of the second toner particle relative to the first toner particle in the toner pack is within a specific range, the toner pack has a storage portion and a discharge member, the discharge member has a receiving port, a discharge port, a fixing part to which the storage portion is fixed, and an inclined surface that causes the toner to move toward the discharge port, and the inclined surface that is the closest to the storage portion is at an angle of 45 degrees or more and less than 90 degrees.

A developer accommodating member for accommodating a developer includes a flexible container provided with a single opening for permitting discharge of the developer, a sealing member bonded to a periphery of the opening and configured to seal the opening, a bonding portion bonding the periphery of the opening and the sealing member, and a reinforcing member. The container includes a fixing portion fixable in a neighborhood of the opening. The opening is formed so as to extend in a longitudinal direction of the container. The reinforcing member is provided on a side opposite from the fixing portion with respect to the opening, and as seen in a direction perpendicular to a plane including the opening. The bonding portion and the reinforcing member at least partially overlap with each other.

A developer accommodating unit for accommodating a developer for image formation includes a flexible container provided with an opening 35a for permitting discharge of the developer, a frame for accommodating the flexible container and for accommodating the developer to be discharged from the flexible container, and an urging member 21 for urging a developer accommodating bag toward the frame for accommodating the developer accommodating bag 16. By this, it is possible to satisfactorily effect discharge of the developer from the flexible developer accommodating bag 16.

A developer accommodating unit for accommodating a developer for image formation includes a flexible container provided with an opening 35a for permitting discharge of the developer, a frame for accommodating the flexible container and for accommodating the developer to be discharged from the flexible container, and an urging member 21 for urging a developer accommodating bag toward the frame for accommodating the developer accommodating bag 16. By this, it is possible to satisfactorily effect discharge of the developer from the flexible developer accommodating bag 16.

A fixing portion 18c for suppressing movement of a developer bag 16 when the developer bag 16 is unsealed by moving a sealing member 19 is provided. By this, unsealing becomes easy.

A toner container includes a toner storage unit, a container base portion including a discharge port provided on an outer surface of the container base portion, the outer surface extending in a first direction, the discharge port communicating with the toner storage unit, and a container shutter configured to be rotatable about a rotation axis extending in a direction along the first direction between a shielding position and an open position. The container base portion includes an engaging portion configured to be engaged with an engaged portion of the image forming apparatus so that rotation of the container base portion with respect to the image forming apparatus about the rotation axis is restricted. At least a part of the engaging portion of the container base portion is exposed from the container shutter in a case where the container shutter is in the shielding position.