A sheet processing apparatus, comprising: a conveyance roller pair that rotates in a certain direction to convey a sheet; a first normal-reverse rotation roller pair that is capable of rotating in a normal direction and a reverse direction and rotates to convey the sheet; a first driver that drives the first normal-reverse rotation roller pair to rotate; and a first driving force transmitter (313, 352) that transmits a driving force of the first driver for rotating the first normal-reverse rotation roller pair in a first specific direction to the conveyance roller pair so as to rotate the conveyance roller pair in the certain direction, and blocks a driving force of the first driver for rotating the first normal-reverse rotation roller pair in the direction opposite to the first specific direction from being transmitted to the conveyance roller pair; characterized by: a second normal-reverse rotation roller pair that is capable of rotating in a normal direction and a reverse direction and rotates to convey the sheet; a second driver that drives the second normal-reverse rotation roller pair to rotate; and a second driving force transmitter (314, 372) that transmits a driving force of the second driver for rotating the second normal-reverse rotation roller pair in a second specific direction to the conveyance roller pair so as to rotate the conveyance roller pair in the certain direction, and blocks a driving force of the second driver for rotating the second normal-reverse rotation roller pair in the direction opposite to the second specific direction from being transmitted to the conveyance roller pair. a conveyance roller pair that rotates in a certain direction to convey a sheet; a first normal-reverse rotation roller pair that is capable of rotating in a normal direction and a reverse direction and rotates to convey the sheet; a first driver that drives the first normal-reverse rotation roller pair to rotate; and a first driving force transmitter (313, 352) that transmits a driving force of the first driver for rotating the first normal-reverse rotation roller pair in a first specific direction to the conveyance roller pair so as to rotate the conveyance roller pair in the certain direction, and blocks a driving force of the first driver for rotating the first normal-reverse rotation roller pair in the direction opposite to the first specific direction from being transmitted to the conveyance roller pair; characterized by: a second normal-reverse rotation roller pair that is capable of rotating in a normal direction and a reverse direction and rotates to convey the sheet; a second driver that drives the second normal-reverse rotation roller pair to rotate; and a second driving force transmitter (314, 372) that transmits a driving force of the second driver for rotating the second normal-reverse rotation roller pair in a second specific direction to the conveyance roller pair so as to rotate the conveyance roller pair in the certain direction, and blocks a driving force of the second driver for rotating the second normal-reverse rotation roller pair in the direction opposite to the second specific direction from being transmitted to the conveyance roller pair. a second normal-reverse rotation roller pair that is capable of rotating in a normal direction and a reverse direction and rotates to convey the sheet; a second driver that drives the second normal-reverse rotation roller pair to rotate; and a second driving force transmitter (314, 372) that transmits a driving force of the second driver for rotating the second normal-reverse rotation roller pair in a second specific direction to the conveyance roller pair so as to rotate the conveyance roller pair in the certain direction, and blocks a driving force of the second driver for rotating the second normal-reverse rotation roller pair in the direction opposite to the second specific direction from being transmitted to the conveyance roller pair.