  We extend the standard model fermions by a mirror copy to realize a
left-right symmetry. During a strongly first order phase transition of the
spontaneous left-right symmetry breaking, the CP-violating reflections of the
mirror fermions off the mirror Higgs bubbles can generate a mirror lepton
asymmetry and an equal mirror baryon asymmetry. We then can obtain an ordinary
baryon asymmetry through the mirror fermion decays where a dark matter scalar
plays an essential role. Benefitted from a parity symmetry for solving the
strong CP problem, the cosmic baryon asymmetry can be well described by the
ordinary lepton mass matrices up to an overall factor. In this scenario, the
Dirac CP phase in the Majorana neutrino mass matrix can provide a unique source
for the required CP violation. Furthermore, the Higgs triplet for type-II
seesaw as well as the first generation of mirror charged fermions can be
allowed at the TeV scale.
