A cartridge comprising: a casing including a developer accommodation part configured to accommodate developer therein; an agitator defining a first rotational axis extending in an axial direction and configured to rotate about the first rotational axis and agitate the developer within the developer accommodation part; a receiving member configured to rotate about a second rotational axis upon receipt of a drive force inputted thereto; a first drive-force transmission member configured to rotate about a third rotational axis upon receipt of the drive force from the receiving member; and a second drive-force transmission member configured to contact the first drive-force transmission member and receive the drive force therefrom, the second drive-force transmission member being configured to rotate about the first rotational axis together with the agitator, characterized by a detected member, wherein the first rotational axis is positioned closer to the second rotational axis than the third rotational axis is to the second rotational axis when projected in the axial direction of the agitator, wherein the second drive-force transmission member is arranged inward of the receiving member in the axial direction, wherein the first drive-force transmission member comprises: a first portion configured to receive the drive force from the receiving member; and a second portion arranged inward of the first portion in the axial direction and integrally formed with the first portion, the second portion being configured to transmit the drive force inputted from the receiving member to the second drive-force transmission member, the detected member being positioned outward of the second drive-force transmission member and inward of the first portion in the axial direction and configured to receive the drive force from the second portion, wherein the second portion includes gear teeth extending in the axial direction, the gear teeth having an inner end portion in the axial direction, wherein the second drive-force transmission member includes gear teeth configured to be engaged with the inner end portion of the gear teeth of the second portion, and wherein the detected member includes gear teeth configured to be engaged with the gear teeth of the second portion, the detected member engaging the second portion at a position outward of the second drive-force transmission member in the axial direction. a casing including a developer accommodation part configured to accommodate developer therein; an agitator defining a first rotational axis extending in an axial direction and configured to rotate about the first rotational axis and agitate the developer within the developer accommodation part; a receiving member configured to rotate about a second rotational axis upon receipt of a drive force inputted thereto; a first drive-force transmission member configured to rotate about a third rotational axis upon receipt of the drive force from the receiving member; and a second drive-force transmission member configured to contact the first drive-force transmission member and receive the drive force therefrom, the second drive-force transmission member being configured to rotate about the first rotational axis together with the agitator, characterized by a detected member, wherein the first rotational axis is positioned closer to the second rotational axis than the third rotational axis is to the second rotational axis when projected in the axial direction of the agitator, wherein the second drive-force transmission member is arranged inward of the receiving member in the axial direction, wherein the first drive-force transmission member comprises: a first portion configured to receive the drive force from the receiving member; and a second portion arranged inward of the first portion in the axial direction and integrally formed with the first portion, the second portion being configured to transmit the drive force inputted from the receiving member to the second drive-force transmission member, the detected member being positioned outward of the second drive-force transmission member and inward of the first portion in the axial direction and configured to receive the drive force from the second portion, wherein the second portion includes gear teeth extending in the axial direction, the gear teeth having an inner end portion in the axial direction, a first portion configured to receive the drive force from the receiving member; and a second portion arranged inward of the first portion in the axial direction and integrally formed with the first portion, the second portion being configured to transmit the drive force inputted from the receiving member to the second drive-force transmission member, the detected member being positioned outward of the second drive-force transmission member and inward of the first portion in the axial direction and configured to receive the drive force from the second portion, wherein the second portion includes gear teeth extending in the axial direction, the gear teeth having an inner end portion in the axial direction, wherein the second drive-force transmission member includes gear teeth configured to be engaged with the inner end portion of the gear teeth of the second portion, and wherein the detected member includes gear teeth configured to be engaged with the gear teeth of the second portion, the detected member engaging the second portion at a position outward of the second drive-force transmission member in the axial direction.