Toner case including internal shutter member, toner supply device, and image forming apparatus

A toner case includes a toner storage portion, a cylindrical portion, a shutter member, and a biasing member. The cylindrical portion has an interior space and communicated with the interior of the toner storage portion through a toner discharge port. An opening is formed at one of opposite ends of the interior space, and a closing wall is formed at the other of the opposite ends of the interior space. The shutter member is supported so as to be slidable in an extension direction of the cylindrical portion, and is movable between a closing position and an opening position. The shutter member at the closing position closes the toner discharge port, and the shutter member at the opening position opens the toner discharge port. The biasing member configured to position the shutter member to the closing position by applying a biasing force to the shutter member.