  The search for light and long-lived particles at the LHC will be intensified
in the upcoming years with a prominent role of the new FASER experiment. In
this study, we discuss how FASER could independently probe such scenarios
relevant for new physics searches at kaon factories. We put an emphasis on the
proposed explanations for the recently observed three anomalous events in the
KOTO experiment. The baseline of FASER precisely corresponds to the proposed
lifetime solution to the anomaly that avoids the NA62 bounds on charged kaons.
As a result, the experiment can start constraining relevant models within the
first few weeks of its operation. In some cases, it can confirm a possible
discovery with up to 10000 spectacular high-energy events in FASER during LHC
Run 3. Further complementarities between FASER and kaon factories, which employ
FASER capability to study di-photon signatures, are illustrated for the model
with axion-like particles dominantly coupled to $SU(2)_W$ gauge bosons.
