  We propose a model of dark sector described by gauged hidden $U(1)_H$
symmetry in which neutrino masses are generated at one-loop level and axion is
induced by assigning Peccei-Quinn charge to fermions in dark sector relevantly.
Then our scenario connects exotic fermion mass generation, neutrino mass matrix
and axion through scalar fields associated with $U(1)_H$ and Peccei-Quinn
symmetry breaking. We investigate neutrino mass formula, lepton flavor
violation, anomalous magnetic moment of muon, dark matter relic density and
axion couplings, which are originated from interactions among our dark sector
and the standard model particles.
