A straddled vehicle comprising: a body frame that extends in a vehicle front-and-rear direction; a pair of left and right side cases (10L, 10R) that are configured to be attachable to and detachable from respective left and right side portions of the body frame; a left rotation supporter that supports an upper portion of the left side case at the body frame such that the left side case is rotatable about a first axis with respect to the body frame with the left side case attached to the body frame; a left rotation attenuator that attenuates rotation of the left side case about the first axis; a right rotation supporter that supports an upper portion of the right side case at the body frame such that the right side case is rotatable about a second axis with respect to the body frame with the right side case attached to the body frame; and a right rotation attenuator that attenuates rotation of the right side case about the second axis, wherein the left rotation attenuator comprises: a first rotation shaft member that extends in a direction of a third axis that is different from the first axis, a first rotation member supported by the first rotation shaft member to be connected to a lower portion of the left side case and rotatable about the third axis with the left side case attached to the body frame, and a first inner outer cylindrical damper (301, 401) provided between the first rotation shaft member and the first rotation member (200, 420), and the right rotation attenuator comprises: a second rotation shaft member that extends in a direction of a fourth axis that is different from the second axis, a second rotation member supported by the second rotation shaft member to be connected to a lower portion of the right side case and rotatable about the fourth axis with the right side case attached to the body frame, and a second inner outer cylindrical damper (301, 401) provided between the second rotatior shaft member and the second rotation member (200, 402). a body frame that extends in a vehicle front-and-rear direction; a pair of left and right side cases (10L, 10R) that are configured to be attachable to and detachable from respective left and right side portions of the body frame; a left rotation supporter that supports an upper portion of the left side case at the body frame such that the left side case is rotatable about a first axis with respect to the body frame with the left side case attached to the body frame; a left rotation attenuator that attenuates rotation of the left side case about the first axis; a right rotation supporter that supports an upper portion of the right side case at the body frame such that the right side case is rotatable about a second axis with respect to the body frame with the right side case attached to the body frame; and a right rotation attenuator that attenuates rotation of the right side case about the second axis, wherein the left rotation attenuator comprises: a first rotation shaft member that extends in a direction of a third axis that is different from the first axis, a first rotation member supported by the first rotation shaft member to be connected to a lower portion of the left side case and rotatable about the third axis with the left side case attached to the body frame, and a first inner outer cylindrical damper (301, 401) provided between the first rotation shaft member and the first rotation member (200, 420), and the right rotation attenuator comprises: a second rotation shaft member that extends in a direction of a fourth axis that is different from the second axis, a second rotation member supported by the second rotation shaft member to be connected to a lower portion of the right side case and rotatable about the fourth axis with the right side case attached to the body frame, and a second inner outer cylindrical damper (301, 401) provided between the second rotatior shaft member and the second rotation member (200, 402). a first rotation shaft member that extends in a direction of a third axis that is different from the first axis, a first rotation member supported by the first rotation shaft member to be connected to a lower portion of the left side case and rotatable about the third axis with the left side case attached to the body frame, and a first inner outer cylindrical damper (301, 401) provided between the first rotation shaft member and the first rotation member (200, 420), and the right rotation attenuator comprises: a second rotation shaft member that extends in a direction of a fourth axis that is different from the second axis, a second rotation member supported by the second rotation shaft member to be connected to a lower portion of the right side case and rotatable about the fourth axis with the right side case attached to the body frame, and a second inner outer cylindrical damper (301, 401) provided between the second rotatior shaft member and the second rotation member (200, 402). a second rotation shaft member that extends in a direction of a fourth axis that is different from the second axis, a second rotation member supported by the second rotation shaft member to be connected to a lower portion of the right side case and rotatable about the fourth axis with the right side case attached to the body frame, and a second inner outer cylindrical damper (301, 401) provided between the second rotatior shaft member and the second rotation member (200, 402).