  CP violating asymmetries in both the production and the decays of $s$-channel
neutral Higgs bosons at $\mu^+\mu^-$ colliders can be large. If the CP
violation occurs in the muon-Higgs coupling, one observes a production
asymmetry with transversely polarized $\mu^+\mu^-$ beams. Likewise if the CP
violation occurs in the top-Higgs or $\tau$-Higgs coupling, one observes an
azimuthal decay asymmetry in $\mu^+\mu-\to t\bar t$ (or $\tau^+\tau^-$). CP
studies at such colliders allow a uniquely clean way of deducing the underlying
CP phases; in turn these parameters would significantly improve our
understanding of baryogenesis.
