  The simplest possibility to explain the baryon asymmetry of the Universe is
to assume that radiation is created asymmetrically between baryons and
anti-baryons after the inflation. We propose a new mechanism of this kind where
CP-violating flavor oscillations of left-handed leptons in the reheating era
distribute the lepton asymmetries partially into the right-handed neutrinos
while net asymmetry is not created. The asymmetry stored in the right-handed
neutrinos is later washed out by the lepton number violating decays, and it
ends up with the net lepton asymmetry in the Standard Model particles, which is
converted into the baryon asymmetry by the sphaleron process. This scenario
works for a range of masses of the right-handed neutrinos while no fine-tuning
among the masses is required. The reheating temperature of the Universe can be
as low as $O(10)$~TeV if we assume that the decays of inflatons in the
perturbative regime are responsible for the reheating. For the case of the
reheating via the dissipation effects, the reheating temperature can be as low
as $O(100)$~GeV.
