  We propose an extended version of the standard model, in which neutrino
oscillation, dark matter, and baryon asymmetry of the Universe can be
simultaneously explained by the TeV-scale physics without assuming unnatural
hierarchy among the mass scales. Tiny neutrino masses are generated at the
three loop level due to the exact $Z_2$ symmetry, by which stability of the
dark matter candidate is guaranteed. The extra Higgs doublet is required not
only for the tiny neutrino masses but also for successful electroweak
baryogenesis. The model provides discriminative predictions especially in Higgs
phenomenology, so that it is testable at current and future collider
experiments.
