  With 6.2 fb^-1 of data collected on the Upsilon(4S), Belle reports its first
measurement of sin 2\phi_1 = 0.45^{+0.43}_{-0.44}(stat)^{+0.07}_{-0.09}(sys).
The result was obtained by fitting the proper time distribution of flavor
tagged and fully reconstructed neutral B mesons decays to five different
charmonia plus a Kshort or Klong channels. In this paper the analysis and
results will be described briefly.
