According to one embodiment, a gyro sensor system including a gyro sensor unit is disclosed. The unit includes a movable body, a spring mechanism, a detector, an adjuster, and a rotation angle acquisition unit. The spring mechanism vibrates the movable body. A detector detects an amplitude of vibration of the movable body due to Coriolis force. The adjuster adjusts a first resonance frequency of vibration of the movable body in free vibration and a second resonance frequency of vibration of the movable body due to Coriolis force on the movable body so that the first and second resonance frequencies are to coincide with each other based on the amplitude of the vibration due to Coriolis force. The rotation angle acquisition unit acquires a rotation angle of the movable body, based on the amplitude of the vibration due to Coriolis force.