Neutrinos are highly populated inside the core of massive stars. They play an important role in the explosion mechanism of core-collapse supernovae. It is known that, almost all of the energy in the gravitational collapse is emitted in the form of neutrinos. They may change their identity through so-called fast flavor conversion induced by mutual forward scatterings. If this fast flavor conversion happens, it may have an impact on the dynamics of supernova explosions, since it may occur near the neutrino sphere. In this presentation, the latest results of our understanding of the neutrino fast flavor conversions in core-collapse supernovae will be reported.