When a predetermined time has passed without detection of engine stall and without detection of the neutral state and without detection of a vehicle starting operation, in a first control state in which a clutch is in a disengaged state, a clutch control system effects transition to a second control state in which transition to a third control state is permitted. When a vehicle starting operation is detected in the second control state B in which the clutch is in the disengaged state, a liquid pressure modulator is driven to effect transition to the third control state in which the clutch is put in the engaged state or a partially engaged state. When an engine stall or the neutral state is detected in the second control state, transition to the first control state A is effected.