  Physics of spin-1 hadron is an unexplored topic in the high-energy region
although spin-1/2 physics has been well investigated in the last decade. It is
important to test our knowledge of hadron spin structure in a quite different
field of spin physics. We discuss tensor structure functions, which do not
exist for the spin-1/2 nucleon, in lepton scattering and in hadron reactions
such as the polarized proton-deuteron Drell-Yan process.
