A toner container is detachably attachable to a developing device. The developing device includes an inlet to be poured with a toner, an inlet shutter to move between a closed position, at which the inlet is closed, and an open position, at which the inlet is open, a biasing mechanism to bias the inlet shutter toward the closed position, an engaged structure provided in the inlet shutter, an engaging structure to engage with the engaged structure and to retain the inlet shutter at the open position against a biasing force of the biasing mechanism, and an engagement releasing structure provided in the inlet shutter and to release an engaging state between the engaged structure and the engaging structure. The toner container includes a contacting surface to contact with the engagement releasing structure and to make the engagement releasing structure release the engaging state.