A bearing system can reduce the relative velocity between a bearing member and a rotation shaft and a rotating member to decrease a load on the bearing member although the rotation shaft and the rotating member rotate in opposite directions with the bearing member therebetween. The bearing system includes a case and a rotation shaft supported by the case. A rotating member is disposed coaxially outside the rotation shaft and rotates in the direction opposite to that of the rotation shaft. A housing is interposed between the rotation shaft and the rotating member and is fixed to the case. A bearing member that rotatably supports the rotating member is interposed between the housing and the rotating member.