A motorcycle includes left and right side cases respectively configured to be attachable to and detachable from left and right portions of a body frame, left and right rotation supporters that respectively support upper portions of the left and right side cases, and left and right rotation attenuation mechanisms that respectively attenuate rotations of the left and right side cases about first and second axes. The left and right rotation attenuation mechanisms respectively include bolts that respectively extend in directions of the first and second axes, rotation members respectively connected to lower portions of the left and right side cases and being supported by the bolts to be rotatable about third and fourth axes that are different from the first and second axes, and inner outer cylindrical dampers respectively provided between the bolts and the rotation members.