The NPB has decided to continue using baseball's manufactured by Mizuno for at least one more year. All twelve NPB have already approved the decision. There will be no changes made to the baseball during the winter, other than the removal of the commissioner's signature.
While a scandal about hidden changes surfaced this year, the league ultimately felt the quality of the baseballs improved enough over the last couple of years to warrant their continued use. Additionally, they felt the "new" standard baseballs managed to strike a fairly decent balance between hitting and pitching, more so than when pitching dominated the leagues during the first two seasons.
Source: Sports Hochi 11/19/2013