Japanese stocks rebounded from Tuesday's sell-off as most Asian markets closed mixed on Wednesday ahead of key central bank decisions as well as major earnings reports due in Japan and South Korea.

The benchmark closed up 281.78 points, or 1.72 percent, at 16,664.82, while the Topix was up 14.73 points, or 1.13 percent, at 1,321.67, getting an additional fillip after Reuters reported, citing Japanese media agency Jiji, that Prime Minister Shinzo Abe and his government will compile a stimulus package of more than $265 billion to prop up Japan's flagging economy.