A multiwire-type, two-dimensional neutron detector system using individual line readout and optical signal transmission is developed for use in the Materials and Life Science Experimental Facility (MLF) at the Japan Proton Accelerator Research Complex (J-PARC). First, irradiation experiments using pulsed neutrons are performed at the J-PARC/MLF, in which the time-of-flight spectra can be measured and clear images produced. The detector system exhibits a gamma-ray sensitivity of 8.2 x 10(9), a position linearity deviation of less than 0.5%, and a spatial response of 1.8mm full width at half maximum. Finally, the validity of the detector system is confirmed via neutron reflectometry using a Ni/Ti multilayer.