  The KOTO experiment recently presented a significant excess of events in
their search for the rare SM process $K_L \to \pi^0\nu\bar{\nu}$, well above
both Standard Model signal and background predictions. We show that this excess
may be due to weakly-coupled scalars that are produced from Kaon decays and
escape KOTO undetected. We study two concrete realizations, the minimal Higgs
portal and a hadrophilic scalar model, and demonstrate that they can explain
the observed events while satisfying bounds from other flavor and beam-dump
experiments. Hadronic beam-dump experiments provide particularly interesting
constraints on these types of models, and we discuss in detail the normally
underestimated uncertainties associated with them. The simplicity of the models
which can explain the excess, and their possible relations with interesting UV
constructions, provides strong theoretical motivation for a new physics
interpretation of the KOTO data.
