Japanese stocks edged up Wednesday, lifted by gains on some Asian markets, but many investors took to the sidelines ahead of an expected monetary policy decision by the US central bank. The benchmark Nikkei 225 Stock Average gained 19.92 points, or 0.23 per cent, to 8741.16 while the broader-based Topix index was up 2.09 points, or 0.28 per cent, at 757.13, according to a report of the German Press Agency "DPA".