  We propose a radiative seesaw model at one-loop level, introducing fields
with large multiplet of $SU(2)_L$. Thanks to large representations, any
additional symmetries are not needed. In this framework, we formulate lepton
and new fermion sector such as mass matrices, LFVs, and muon $g-2$.
Furthermore, we show our cut-off scale via RGEs of $SU(2)_L$, and numerical
analysis at a benchmark point included in dark matter candidate. Finally, we
brief discuss possibility to detect at colliders.
