A cartridge for accommodating developer includes a detected member configured to be detected by an external first sensor, and a drive-force transmission member configured to transmit a drive force to the detected member upon receipt of the drive force from outside. The detected member is configured to rotate in a first direction about a first rotational axis extending in an axial direction. The detected member includes: a receiving part configured to contact the drive-force transmission member to receive the drive force therefrom; and a first detected part. A portion of the first detected part and a portion of the receiving part are arranged at the same position as each other in the axial direction.