  Recently, Kajiyama, Okada and Yagyu (KOY) proposed an electron/muon specific
two Higgs doublet model. In this model, an S3 symmetry suppresses flavor
changing neutral currents instead of a Z2 symmetry. In the "Type I" version of
the model, the heavy Higgs bosons have a greatly enhanced coupling to electrons
and muons. KOY studied the phenomenology of the heavy Higgs bosons at the LHC.
In this paper, the phenomenology at electron-positron colliders is studied. For
the heavy Higgs mass range between 150 and 210 GeV, bounds from LEP-200 are
stronger than those from the LHC. The model allows for the interesting
possibility that muon pair production at the ILC can be mediated by s-channel
Higgs exchange. This requires an energy scan. The scanning rate and necessary
resolution are discussed.
