The decay \(B^0 \rightarrow K^0_S \pi ^0\) is dominated by \(b \rightarrow s\) loop amplitudes, making it a sensitive probe for physics beyond the Standard Model (SM). This channel plays a key role in the “ \(K\pi \) puzzle,” where the amplitudes of four decays \(B \rightarrow K\pi \) are interrelated. Recent Belle II results have alleviated some of the existing tensions in these measurements. We present a preliminary sensitivity study based on Monte Carlo simulations, with the aim of improving the measurement of CP violation in this channel using the combined Belle + Belle II dataset. The Belle analysis will be updated using a multivariate approach for \( K^0_S\) and \(\pi ^0 \) , while the Belle II results will include the Run II dataset. The excellent neutral particle reconstruction capability of Belle II allows for precise measurements of the CP-violating parameters \( A_{CP} \) and \( S_{CP} \) , as well as the branching fraction of \( B^0 \rightarrow K^0_S \pi ^0 \) .