A utilizing device includes a utilizing-side inference unit that uses a utilizing-side inference network to perform inference from target data, and a utilizing-side transmitting unit that transmits the target data to a learning device when the degree of certainty of the inference result inferred by the utilizing-side inference network is lower than a predetermined criterion. The learning device includes a learning-side inference unit that uses a learning network functioning as a teacher model of a utilizing-side inference network to perform inference from the received target data to generate learning data, a learning unit that generates updated weighting coefficient information indicating weighting coefficients updated by relearning the learning-side inference network which has the same network structure as the utilizing-side inference network by using the learning data, and a learning-side transmitting unit that transmits the updated weighting coefficient information to the utilizing device to update the utilizing-side inference network.