An assist system includes a fist belt worn on an upper body part of a user, a second belt worn on a knee of the user, a wire, a motor coupled with a first end of the wire and disposed on the first or second belt, a drive controller that controls drive of the motor, a gyro sensor that is disposed on the second belt and that measures an angular velocity about a direction perpendicular to the direction of the wire, and a controller. When the angular velocity is greater than or equal to a first threshold with a first tension being applied to the wire using the motor, the controller outputs first information. A second end of the wire is coupled with the second belt when the motor is disposed on the first belt but coupled with the first belt when the motor is disposed on the second belt.