  The Lepton Portal Dark Matter model, in which dark matter states only
coupling to the charged leptons, can explain the excess of the muon anomalous
magnetic moment measured by the Muon $g - 2$ experiment. In this paper, we
demonstrate that real, charge-neutral scalar dark matter with a large number of
internal degrees of freedom and a mass approximately degenerate with the
charged fermionic mediator state can accommodate the $(g - 2)_\mu$ excess. The
model remains consistent with the dark matter relic abundance, direct
detection, and indirect detection constraints. The dark matter and its charged
fermion partner masses are constrained to be below around 200 GeV. The
high-luminosity LHC and future lepton colliders, as well as indirect searches
at CTA and GAMMA-400, can test this scenario.
