A clutch structure, constructed without a one-way clutch, remains engaged until the input side rotational speed becomes relatively low. A pressure plate presses a group of plates directly or indirectly by moving in the direction of an axis, bringing the group of plates into a press contact state. An input side press body turns around the axis with the rotation of a clutch housing, presses the pressure plate to the side of the group of plates by centrifugal force generated during the turning, and moves in a direction away from the axis. A roller retainer presses the group of plates directly or indirectly by moving in the direction of the axis, bringing the group of plates into a press contact state. An output side press body turns around the axis with the rotation of an output side clutch member, presses the roller retainer to the side of the group of plates by centrifugal force generated during the turning, and moves in a direction away from the axis.