He has been working on Belle at KEK, and has been co-produced together with BaBar at SLAC the experimental evidence of the Kobayashi-Maskawa theory as well as other remarkable physics results about the CP asymmetry in the B meson decays. Besides the physics research work, he is also involved in the detector readout electronics and the data acquisition system. The COPPER readout system, of which detail is presented in this seminar, is one of his major achievements toward the severer trigger rate and the larger data size expected in the luminosity-upgraded B-factory experiment.