Kaon and Muon Decay Phenomenology

Theoretical aspects of kaon and muon decays are reviewed. In particular, three topics on kaon and muon decays, namely $K \to \pi\nu \bar{\nu}$ processes, T violation in $K^+ \to \pi^0\mu^+ \nu$ decay and lepton flavor violation in muon decay are considered. Theoretical backgrounds and possible significance on new physics searches by these processes are discussed.