  We observe evidence for CP violation in the decay $D^+\rightarrow K^0_S\pi^+$
using a data sample with an integrated luminosity of 977 fb$^{-1}$ collected by
the Belle detector at the KEKB $e^+e^-$ asymmetric-energy collider. The CP
asymmetry in the decay is measured to be $(-0.363\pm0.094\pm0.067)%$, which is
3.2 standard deviations away from zero, and is consistent with the expected CP
violation due to the neutral kaon in the final state.
