Recent news from $K_L \to \pi^0 \nu\bar\nu$ and perspectives KOTO

Recent results to search for the decay $K$$_{L}$ → π$^{0}$$ν$$\bar{v}$ with the data collected in 2015 in the KOTO experiment are described. The best upper limit on the branching fraction of the decay in the direct search was obtained to be 3 × 10$^{−9}$ at the 90% confidence level. We also present the analysis status of the data taken in 2016-2018, and the detector upgrade done in 2018. The sensitivity is projected with the detector upgrade and a planned accelerator upgrade. Future plan to further explore $K$$_{L}$ → π$^{0}$$ν$$\bar{v}$ with a new beamline and a new detector is explained.