  We discuss a mechanism where charged lepton masses are derived from one-loop
diagrams mediated by particles in a dark sector including a dark matter
candidate. We focus on a scenario where the muon and electron masses are
generated at one loop with new ${\cal O}(1)$ Yukawa couplings. The measured
muon anomalous magnetic dipole moment, $(g-2)_\mu$, can be explained in this
framework. As an important prediction, the muon and electron Yukawa couplings
can largely deviate from their standard model predictions, and such deviations
can be tested at High-Luminosity LHC and future $e^+e^-$ colliders.
