The benchmark FTSE Bursa Malaysia KLCI rose 0.2 per cent to 1,658.73 points.
The ringgit ended little changed at 4.135 against the dollar.
On Wednesday, the BoJ left interest rates unchanged at negative 0.1 per cent, and modified its policy framework to target the shape of the Japanese yield-curve, according to a report in the Nikkei Asian Review (NAR).
The BoJ, which currently buys government bonds at a rate of 80 trillion yen a year, will allow its base money target to fluctuate in order to keep 10-year bond yields around current levels of zero per cent, according to the NAR report. It is also implementing other moves to maintain stability.
On the KLCI, 14 of the 30 constituents ended higher Wednesday and two closed unchanged, while overall advancing issues outnumbered declining ones 460 to 329.
Genting Malaysia advanced 4.2 per cent to RM4.70, leading gains on the KLCI.
YTL rose 2.3 per cent to RM1.80 . The integrated infrastructure conglomerate is the best performing stock on the KLCI so far in September, advancing over 7 per cent, according to the NAR report.
Mobile operator Axiata, which had risen 2.3 per cent Tuesday, slipped 1.7 per cent to RM5.30.
Malayan Banking fell for a sixth consecutive session to end 0.5 per cent lower at RM7.76.